Ambience of Physico-Chemical Characteristics to Actinobacterial Density in the Chennai Coast of the Bay of Bengal, India

Indian Journal of Geo-Marine Sciences Vol. 42(2), April 2013, pp. 254-265

Ambience of physico-chemical characteristics to actinobacterial density in the Chennai coast of the Bay of Bengal, India

S. Gnanam*, K. Sivakumar, S. Vijayalakshmi & T. Balasubramaniyan, Faculty of Marine Sciences. CAS in Marine Biology, Annamalai University, Parangipettai-608502, India *[Email: [email protected]]

Received 8 May 2011; revised 13 January 2012

Present study consists seasonal abundance and relationship of actinobacteria with the important chemical characteristics of the marine environment in both water and sediments. Actinobacterial density exhibited clear seasonal variations, being highest (38 × 104 CFU/g dry wt) in monsoon and lowest (13 × 104 CFU/g dry wt) in summer, 2009. Seasonal variations of actinobaterial diversity showed is positive correlation with water nutrients such as phosphate , nitrite, nitrate and silicates and with sediment nutrients such as clay soil, total organic carbon, total nitrogen and total phosphorus. Negative correlation was observed with water temperature, salinity and pH. Monsoon and summer seasons exhibited the major influence on the actinobacterial population in the marine environment of Chennai coast.

[Keywords: Physico-chemical, Nutrients, Actinobacteria, Population density, Bay of Bengal, India]

Introduction Nadu (Bay of Bengal) in relation to the prevailing Environmental conditions such as topography, physico-chemical characteristics. water movement and stratification, temperature, pH, Material and Methods salinity, light availability, nutrients, sediment and soil 1 In the present investigation, water and sediment texture determine the composition of the biota . 2 3 samples were collected from four marine locations Increased temperature , low salinity , increased water 4,5 (Ennore (Lat 13° 12’ 18.81’’ N; Long 80° 19’ 54.25’’ and sediment nutrients and availability of organic 6 E), Chennai harbour (Lat 13° 7’ 50.32’’ N; Long 80° 23’ matter have been found to favor the growth and 46.20’’E) Cooum (Lat. 13° 4' 1.23" N; Long. 80° 22' distribution of microorganisms. In the case of 55.81" E) and Muttukadu (Lat. 12° 48’ 25.32°’’N; and actinobacteria, sediment texture, pH, temperature and 7,8 9 Lang. 80º 17’ 39.81’’E) situated perpendicular to the salinity and organic carbon and total nitrogen have seaward side of Chennai coast of bay of Bengal (Fig. 1). been found to influence their distribution and density in the marine environment. Among all the marine microbes, bacteria and fungi have been studied well for their ecology and ecosystem functions whereas marine actinobacteria have not been given that much of attention, though their occurrence is ubiquitous and reported from deep ocean floor to coral sediments10, sea grass environment11, estuarine samples12 etc. Several works on the isolation of actinobacteria have been carried out around the world: from oceans13-17 and many marine habitats18-22. However, exploration of actinobacteria in partially offshore region of the marine environment (10 km in the sea from the coast, situated away from the immediate influence of the coast) is very much limited. Considering this, the present study was carried out to record the actinobacterial population Fig. 1—Map showing the study areas along the Chennai coast of density in four locations in the east coast of Tamil the Bay of Bengal. GNANAM et. al: ACTINOBACTERIAL DENSITY IN THE CHENNAI COAST 255

Surface water and sediment samples were collected aseptically for one week and incubated at 55°C for 5 from Chennai coast at four stations during January to min28.

December 2009 while cruising in the Sagar Paschimi For easy interpretation of data on the influence of coastal research vessel at 10 km distance of coastal the physico-chemical features on the actinobacterial areas in order to record various physico-chemical population density, a calendar year of study was parameters and sediment actinobacterial density. divided into four seasons viz. postmonsoon season Air, surface water and sediment temperatures were (January to March), summer season (April to June), noted with the help of a Celsius thermometer. Salinity premonsoon season (July to September) and monsoon was recorded using a hand Refractometer (Atago, season (October to December) based on the northeast Japan). Water pH (Negative logarithm of hydrogen- monsoon which is prevalent during October- ion concentration) was noted by a calibrated pH pen December months of every year along the southeast (pH Scan 1 Tester-Eutech Instrument, Singapore). coast of India.

Dissolved oxygen was measured, using the modified -1 -4 23 Dilutions (10 - 10 ) of one gram of sediments in Winkler’s titration method . Water samples were sterile 100% aged seawater were prepared and plated collected from the sampling locations using clean on Starch-Casein Agar Medium and incubated at polyethylene bottles and were transported to the 28°C for 2-4 weeks to isolate the sporulating laboratory by keeping them in a portable ice box. actinobacteria. Actinobacterial colonies that appeared Concentrations of water nutrients viz. phosphate on the petri plates were counted from 5th day onwards, (PO4), nitrite (NO2), nitrate (NO3) and silicate (SiO3) up to 28th day. Strains were sub-cultured onto the was determined, following the standard methods23, 24. same medium (medium with 100% sea water) and Sediment samples were collected by employing an preserved in 20% glycerol at -80°C until use. alcohol rinsed and air-dried small Peterson’s grab. The central portion of the collected sediments was Results aseptically transferred into sterile polyethylene bags using sterile spatula and were transported to the Physico-chemical parameters laboratory by keeping them in a portable ice box. Air- Monthly variations in the physico-chemical dried sediment samples were ground to fine powder parameters viz. temperature (air and water), salinity, using pestle and mortar. Total organic carbon was pH, dissolved oxygen, nitrite, nitrate, phosphate, determined using potassium chromate as an oxidizing ammonia and silicate were recorded for a period of 25 one year from January to December 2009. reagent . Total nitrogen in the sediments was determined by Kjeldahl method24 and total Air temperature varied between 26.6°C and phosphorus was determined by the method of 35.8°C. The minimum (26.6°C) was recorded at APHA24. For soil texture analysis, sediment was air- station 3 in October 2009 while the maximum dried and sieved through a mechanical sieve to (35.8°C) was recorded at station 4 in May 2009 remove shells, coral pieces etc. Dried sediment (Fig. 2). Surface water temperature ranged from sample was subjected to size fractionation by 23.2°C and 32.2°C. Minimum (23.2°C) was noticed at following the modified procedure of Udden26. station 3 in October 2009 while the maximum Sediment sample (100 g) was weighed and sieved (32.2°C) was recorded at station 2 in May 2009 (Fig. through a mesh (62 µ) for 10 minutes in a sieve 3). Water pH ranged between 7.1 and 8.3. Minimum shaker. The sample that remained in the sieve was (7.1) was recorded at station 3 in October 2009 while weighed and treated as sand. The sediment samples the maximum (8.3) was noticed at stations 1 and 3 in which passed through the 62 µ sieve were the silt and May 2009 (Fig. 4). Salinity fluctuation was between clay. The silt and clay were then fractionated by 27.0‰ and 35.0‰. Minimum (27.0‰) was recorded means of pipette method27. at station 3 in October 2009 while the maximum

For microbiological analysis, sediment samples (35.0‰) was observed at stations 1 and 2 in May 2009 (Fig. 5). were collected by employing an alcohol rinsed and air- dried small Peterson’s grab. Central portion of the Dissolved oxygen content varied from 3.71 and collected sediments was aseptically transferred into 5.33 mg/l. Minimum (3.71 mg/L) was recorded at sterile polyethylene bags using sterile spatula and station 3 in May 2009 while the maximum (5.33 mg/l) brought to the laboratory. Samples were then air-dried was observed at station 4 in October 2009 (Fig. 6). 256 INDIAN J. MAR. SCI., VOL. 42, NO. 2, APRIL 2013

Figs. 2-9Air temperature variations recorded at four stations; (3)-Surface water temperature variations recorded at four stations; (4)-Water pH variations recorded at four stations; (5)-Salinity variations recorded at four stations; (6)-Dissolved oxygen content variations recorded at four stations; (7)-Inorganic phosphate content variations recorded at four stations; (8)-Nitrite content variations recorded at four stations; (9)-Nitrate content variations recorded at four stations. GNANAM et. al: ACTINOBACTERIAL DENSITY IN THE CHENNAI COAST 257

Water nutrients morphology57 for one year from January to December Phosphate concentration ranged from 0.46 to 4.00 2009 is shown in Fig. 18. Actinobacterial density µmol/L. Minimum (0.46 µmol/L) was recorded at enumerated from the four stations varied from 13 × station 3 in May 2009, whereas the maximum 104 to 38 ×104 CFU/ g dry wt with the minimum (13 (4.0 µmol/L) was noticed at station 3 in October 2009 ×104 CFU/ g dry wt) at station 2 in May 2009 and the (Fig. 7). Nitrite content ranged from 0.44 and 1.16 maximum (38 × 104 CFU/g dry wt) at station 3 in µmol/L. Minimum (0.44 µmol/L) was recorded at October 2009. Analysis of variance (ANOVA) station 3 in May 2009 while the maximum (1.16 between different physico-chemical parameters is µmol/L) was observed at station 3 in November 2009 given in Table 1 and the correlation co-efficient (Fig. 8). Nitrate content ranged between 4.1 and 14.2 worked out for different stations are also given µmol/L. The minimum (4.1 µmol/L) was observed in (Tables 2-5). May 2009 at station 3 while the maximum (14.2µmol/L) was recorded at station 3 in November, 2009 (Fig. 9). Discussion Silicate content ranged between 4.37 and 39.86 µmol/L. Physico-chemical parameters of the marine The minimum (4.37 µmol/L) was recorded at station 4 environment observed in the present study areas in May 2009 while the maximum (39.86 µmol/l) was showed both spatial and temporal variations. Higher recorded at station 3 in October 2009 (Fig. 10). air temperature (35.7°C) was noticed at station 4 in May 2009 and it could be attributed to higher solar Sediment Nutrients radiation in the summer season. Such higher summer Monthly variations in the concentration of total air temperature is usual in this part of the coast29. organic carbon, total nitrogen and total phosphorus Similar observations have been made from Egypt30. recorded for one year from January to December 2009 Minimum (26.6°C) was observed at station 3 in are shown in Figs. 11-13. Total organic carbon October 2009 (monsoon), which could be due to the content ranged between 0.74 and 10.17 mg C/g. cloudy sky. While the lower air temperature also has Minimum (0.74 mg C/g) was recorded at station 4 in reported during the monsoon season and attributed it to May 2009 while the maximum (10.17 mg C/g) was the effect of atmospheric cooling31. observed at station 3 in October 2009. Total nitrogen Generally, sea surface water temperature is content ranged from 4.11 and 8.87 µg/g. Minimum influenced by the sunshine, evaporation, cool (4.11 µg/g) was observed at station 4 in May 2009 freshwater influx and admixture of ebb and flow from while the maximum (8.87 µg/g) was also recorded at the adjoining neritic waters. Maximum surface water station 4 in October 2009. Total phosphorus content temperature (32.2°C) was noticed at station 2 in May ranged from 0.59 and 2.98 µg/g. The minimum 2008, in summer. Similar summer maximum (0.43 µg/g) was recorded at station 3 in May 2009 temperature has been reported31 and 27-36°C has been while the maximum (2.02 µg/g) was noticed at station recorded from the Gulf of Mannar region31. Minimum 3 in October 2009. (23.2°C) surface water temperature was at station 3 in October (monsoon), due to land drainage from the Soil texture Coovum during this period. Similar observations have Sand content ranged from 51.03 to 98.12%. The 33, 34 maximum (98.12%) was observed at station 1 in been made from the Vellar estuary . January 2009 and the minimum (51.03%) was noticed In the study areas, water temperature ranged from in station 3 in November 2009. The silt content 23.2 to 32.2ºC and air temperature, from 26.6 to 35.8 ranged from1.43 to 29.97%. Maximum (29.97%) silt ºC. Whereas, 27-34ºC surface water temperature have also recorded in the Tuticorin which is also a part of was noticed at station 1 in November 2009, whereas 35 minimum was (1.43%) at station 4 in December 2009. the Gulf of Mannar . Such variations observed in temperature could be ascribed to the intensity of Clay content ranged from 0.42 to 28.72%. Maximum 36 (28.72%) was at station 3 in November 2009 and the prevailing currents causing mixing of water . minimum (0.42%) was at station 4 in May 2009 Statistical analysis showed positive correlation between (Figs. 14-17). air and surface water temperature at different stations: r= 0.897 at station 1, r= 0.866 at station 2, r= 0.907 at Microbiological analysis station 3 and r= 0.953 at station 4, revealing the Monthly variations in sediment actinobacterial influence of air temperature over the surface water population density were recorded according to colony temperature (Tables 2-5). 258 INDIAN J. MAR. SCI., VOL. 42, NO. 2, APRIL 2013

Figs. 10-17—Silicate content variations recorded at four stations; (11)-Sediment total organic carbon content variations recorded at four stations; (12)-Sediment total nitrogen content variations recorded at four stations; (13)-Sediment total phosphorus content variations recorded at four stations; (14)— Monthly variations in sediment composition recorded at station 1; (15)-Monthly variations in sediment composition recorded at station 2; (16)-Monthly variations in sediment composition recorded at station 3; (17)-Monthly variations in sediment composition recorded at station 4. GNANAM et. al: ACTINOBACTERIAL DENSITY IN THE CHENNAI COAST 259

observed at station 3 in October 2009 (monsoon) and it was lower (2.45 µmol/L) at station 3 in May 2009 (summer). Higher concentration of phosphate recorded at station 3 could have been derived from the industrial effluents discharged, during the monsoon season.

Biogeocycling and distribution of nutrients in the sea are ultimately driven by solar energy, continuous supply of nutrients and fresh water inflow39. Nitrite is a momentary nutrient and therefore its concentration is determined by the balance between the formation

and distribution. Higher concentration of nitrite (14.2 Fig. 18—Actinobacterial density variations recorded in sediment µmol/mL) was observed in November, 2009 at station samples at four stations. 3 (monsoon). Increase in nitrogenous nutrients mainly through freshwater input and terrestrial runoff during Water pH (Hydrogen-ion concentration) plays an the monsoon season would definitely contribute to the important role by influencing all the aquatic organisms 40, 41 including microbes. pH also affects other parameters higher nitrite concentration . Lower concentration of nitrite (0.44 µmol/L) recorded at station 3 in May such as dissolved oxygen and total alkalinity. pH range 37 p was reported from 6 to 8 in Mumbai coast . Water pH (summer), could be due to higher salinity, H and uptake by phytoplankton during the summer season. recorded in the present study was lower (7.1) at station 3 in October 2009 (monsoon) while the maximum (8.3) This is evidenced by the negative correlation obtained was at stations 1 and 3 in May 2009 (summer). Such a between salinity and nitrite (r = -0.822, P<0.01%) and pH and nitrite (r = -782, P<0.01%) at station 3. summer increase in pH could be due to higher phytoplankton photosynthetic activity38. A significant Minimal nitrate concentration (4.1µmol/L) was positive correlation obtained between salinity and pH recorded at station 3 in May 2009 (summer), probably (r= 0.931 at station1, r=0.909 at station 2, r=0.891 at due to the phytoplankton utilization of this nutrient. 42 station 3 and r=0.884 at station 4) has revealed that Similarly, lower nitrate value (4.2 µg/L) in summer 31 salinity has influence over pH (Tables 2-5). and minimal concentration (3.7 ± 1.4 µM) in spring , Salinity variations affect the biological caused by assimilation by phytoplankton and other characteristics of the marine environment. In the aquatic plants, have been reported. present study, at all the four stations, salinity was Silicate values were lower at all the stations in May minimum during the monsoon (October to December 2009 (summer), which could be due to the utilization 2009), due to freshwater discharge caused by by phytoplankton especially diatoms43. Higher precipitation. Salinity was maximum during the concentration of silicate (39.86 µmol/l) observed at summer due to higher solar radiation causing station 3 in October 2009 (monsoon) could be evaporation and absence of rainfall and freshwater ascribed to the input of freshwater due to rain fall. input. Statistical analysis showed positive correlation Significant positive correlation obtained between (r= 0.880 at station 1, r= 0.917 at station 2, r= 0.933 at dissolved oxygen and silicate (r= 0.827 at station 1, r= station 3, r= 0.920 at station 4, P< 0.01%) between air 0.694 at station 2, r= 0.884 at station 3, r= 0.957 at temperature and salinity, revealing that salinity is station 4) (Tables 2-4) reveals that silicate has influenced by temperature. influence over phytoplankton photosynthesis44. Recording lower value of dissolved oxygen Sediment TOC has been reported by many workers: (3.71mg/L) in May 2009 (summer) at station 3 could (4.75 and 4.70 mg C/g) 45; (1.43 ±0.17 %) 46. In the be due to the decomposition of biota and uptake of present study, higher concentration of sediment total oxygen by the marine organisms. Higher value of organic carbon (10.01 mg C/g) was recorded at station dissolved oxygen (5.33mg/L), observed at station 4 in 3 in October 2009 (monsoon). This could be attributed October 2009 (monsoon) could be correlated with to the transport of organic matter from the coastal areas fresh water discharge and mixing. to the offshore region. In addition to this, large amount Many aquatic organisms utilize both organic and of dead plank tonic matter that settles at the bottom inorganic forms of phosphorus for their metabolism. may get oxidized and decomposed into organic carbon Higher concentration of phosphate (5.42 µmol/L) was and laid in the sediments (Martin, 1970) 47.. 260 INDIAN J. MAR. SCI., VOL. 42, NO. 2, APRIL 2013

Table 1—Analysis of variance (F) – values in the environmental parameters between four stations.

Source of variation SS df MS F F crit P - value Air temperature Rows 381.2342 11 34.65765 122.3102 2.093254 <0.05 Columns 1.374167 3 0.458056 1.616523 2.891564 NS Water temperature Rows 162.9656 11 14.81506 36.9717 2.093254 <0.05 Columns 12.67896 3 4.226319 10.54699 2.891564 <0.05 pH Rows 4.570625 11 0.415511 33.83907 2.093254 <0.05 Columns 0.102292 3 0.034097 2.776864 2.891564 NS Salinity Rows 216.7292 11 19.70265 86.45152 2.093254 <0.05 Columns 15.22917 3 5.076389 22.27424 2.891564 <0.05 Dissolved oxygen Rows 3.06048 11 0.278225 33.92619 2.093254 <0.05 Columns 1.307495 3 0.435832 53.14431 2.891564 <0.05 Inorganic phosphate Rows 36.10526 11 3.282297 31.50121 2.093254 <0.05 Columns 6.694464 3 2.231488 21.41628 2.891564 <0.05 Nitrite Rows 1.130748 11 0.102795 18.60443 2.093254 <0.05 Columns 0.021189 3 0.007063 1.278287 2.891564 NS Nitrate Rows 266.5106 11 24.22824 32.87676 2.093254 <0.05 Columns 5.150355 3 1.716785 2.32961 2.891564 NS Silicate Rows 3733.779 11 339.4344 54.53353 2.093254 <0.05 Columns 545.117 3 181.7057 29.19283 2.891564 <0.05 Total organic carbon Rows 102.0604 11 9.278218 29.67451 2.093254 <0.05 Columns 97.47527 3 32.49176 103.9183 2.891564 <0.05 Sediment total phosphate Rows 8.59834 11 0.781667 9.465569 2.093254 <0.05 Columns 3.11235 3 1.03745 12.56296 2.891564 <0.05 Sediment total nitrogen Rows 55.48817 11 5.044379 62.10087 2.093254 <0.05 Columns 5.47935 3 1.82645 22.48525 2.891564 <0.05 Sand Rows 3676.033 11 334.1848 4.473486 2.093254 <0.05 Columns 427.8208 3 142.6069 1.908974 2.891564 NS Silt Rows 2087.959 11 189.8144 4.719097 2.093254 <0.05 Columns 262.356 3 87.45201 2.1742 2.891564 NS Clay Rows 366.4482 11 33.31347 1.533587 2.093254 <0.05 Columns 31.6491 3 10.5497 0.485656 2.891564 NS Actinobacteria density Rows 882.7292 11 80.24811 15.62161 2.093254 <0.05 Columns 569.7292 3 189.9097 36.96903 2.891564 <0.05 Significant at 5% level (P<0.05) NS= Not Significant. GNANAM et. al: ACTINOBACTERIAL DENSITY IN THE CHENNAI COAST 261

Maximum total nitrogen value in the sediments was 8.87 µg/g at station 4 in October 2009 (monsoon). The lower value of nitrogen (4.11µg/g) was at station 3 in May 2009 (summer). Such a fluctuation of total nitrogen in the sediments was similar to TOC fluctuation, indicating the relationship of TOC with the sediment nutrients. This is evidenced by the significant positive correlation between TOC and nitrogen (r= 0.908 at station 1, r= 0.885 at station 2, r= 0.927 at station 3, r= 0.985 at station 4) and phosphorus (r = 0.971 at station 1, r= 0.888 at station 2, r= 0.930 at station 3, r= 0.843 at station 4 (Tables 2-5).

Detritus is the main source of organic phosphorus in the sediments. It gets bound with shells and bones of invertebrate animals48 and when the shells break, phosphorus is released into the sediments and water. Presently, higher phosphorus content (2.98 g/g) was observed at station 3 in October 2009 (monsoon). Minimum (0.59 mg/g) was recorded also at station 3 in May 2009 (summer). Similar findings on the total sediment phosphorus (0.77 to 0.77 mg/g) have been reported from the Vellar estuary45 and Nigeria46.

Sediment soil texture also plays an important role in the distribution and abundance of marine microorganisms. Maximum sand (98.12%) was observed at station 1 during postmonsoon (January); silt (29.97%) at station 1 in November (monsoon) and clay (28.72) at station 3 during the postmonsoon (January) season. Sediment texture of station 3 was clayey silt with low sand than the other 3 stations as it is located near the mouth of the river Cooum. Soil composition of the Vellar estuary [sand (44.30%), silt (27.43%) and clay (28.30%)] and reported that the variation in the soil texture was due to the influence of tides and monsoonal floods45. Clayey sediments contain sufficient nutrients for good propagation of the microorganisms than sandy sediments49 and support higher actinobacterial populations50. In the present study also, positive correlation was obtained between the actinobacterial density with clay soil (r= 0.654 at station 1, r= 0.252 at station 2, r= 0.382 at station 3, 0.270 at station 4).

Actinobacteria are geographically spread across the oceanic realms and their distribution is mainly influenced by various parameters such as temperature, salinity, underlying geochemistry and ocean currents. In the Gulf of Mannar, higher actinobacterial population density (38 × 104 CFU/g dry wt) was recorded in the sediments at station 3 in October 2009 4 (monsoon) and lower density (13 × 10 CFU/g dry wt) 262 INDIAN J. MAR. SCI., VOL. 42, NO. 2, APRIL 2013

GNANAM et. al: ACTINOBACTERIAL DENSITY IN THE CHENNAI COAST 263

was recorded at station 2 in May 2009 (summer). This ange is similar to those reported from the marine sediments of the Bay of Bengal50-53.

Sediment nutrients especially total organic carbon (TOC) can significantly influence the actinobacterial population density9 and the actinobacteria can survive well as they are saprophytic organisms, depending on the availability of carbon50. This is evidenced by the significant positive correlation obtained in the present study between the sediment TOC and actinobacterial population density (r= 0.577 in station 1, r= 0.586 in station 2, P< 0.05% and r= 0.750 in station 3 and r= 0.756 in station 4, P<0.01%).

Nutrients are responsible for promoting the bacterial growth and diversity in the marine environment54,55. This is evident from the positive correlation obtained between the sediment nutrients with the actinobacterial population density at all the four stations studied (Total nitrogen: (r= 0.777 at station 1, r= 0.837 at station 2, r= 0.847 at station 3, r= 0.766 at station 4), total phosphate: (r= 0.725 at station 1, r= 0.843 at station 2, r= 0.840 at station 3, r= 0.608 at station 4). This lends support to the findings in Pitchavaram waters56 and Vellar estuary45.

Actinobacterial population density in sediments showed negative correlation with water temperature (r= -0.646 at station 1, r= -0.544 at station 2, r= -0.693 at station 3, r= -0.744 at station 4); salinity (r= -0.645 at station 1, r= -0.717 at station 2, r= -0.645 at station 3, r= -0.617 at station 4) and pH ( r= -0.670 at station 1, r= -0.578 at station 2, r= -0.768 at station 3, r= -0.584 at station 4) and positive correlation with water phosphate (r= 0.728 at station 1, r= 0.847 at station 2, r= 0.792 at station 3, r= 0.977 at station 4), nitrite (r= 0.751 at station 1, r= 0.793 at station 2, r= 0.771 at station 3, r= 0.997 at station 4), nitrate (r= 0.569 at station 1, r= 0.800 at station 2, r= 0.740 at station 3, r= 0.760 at station 4) and silicates (r= 0.729 at station 1, r= 0.839 at station 2, r= 0.802 at station 3, r= 0.674 at station 4), suggesting that the sediment microbial populations are also influenced by the overlying water column properties, in addition to sediment characteristics.

Acknowledgement Authors are thankful to the Dean and Director, Faculty of Marine Sciences, Annamalai University for providing facilities and financial support to carry out the work.

264 INDIAN J. MAR. SCI., VOL. 42, NO. 2, APRIL 2013

References 18 Coloquhoun, J.A., Mexson, J., Goodfellow, M., Ward, A.C., 1 Karande, A. N. N. A., Use of epifaunal communities in Horikoshi, K. & Bull, A.T., Novel rhodococci and other pollution monitoring, J. Environ. Bio., 3 (1991) 191-200. mycolate actinomycetes from the deep sea, Anto. Van 2 Armcanz A, Australian guidelines for water quality Leeuwenhook, 74 (1998) 27-40. monitoring and reporting (Environment and Conservation 19 Takizawa, M., Hill, R.T & Colwell, R. R., Isolation and Council & Agriculture and Resource Management Council diversity of Actinomycetes in the Chesapeake Bay, Appl. of Australia and New Zealand) 2000, pp.26. Environ. Microbiol., 59 (1993) 997-1002. 3 Lucena, J.J., Gfirate, A & Carpena, O., Lolium multiflorum 20 Goodfellow M & Haynes J A, Actinomycetes in marine uptake of iron supplied as different synthetic chelat, Plant & sediments, In: Biological, Biochemical and biomedical Soil, 112 (1988) 23-28. Aspects of Actinomycetes (Eds.), edited by L. Oritz-Oritz, 4 Carlucci, A.F., Nutrients and microbial response to nutrients L.F. Bojalil & V. Yakoleff, (Academic Press, New York, in seawater. In: Effect of the Ocean environment on London) 1984 pp.453-472. microbial activities by R.R. Colwell and R.Y. Morita (ed.), 21 Bercina, I., Iriberri, J. & Egea, L., Enumaration, isolation and (University Park Press, Baltimore), 1974, pp. 245-248. some physiological properties of actinomycetes from sea 5 Paramasivam, S., Studies on histamine producing bacteria of water and sediments, Syst. Appl. Microbiol., 10 (1987) 85-91. the mangrove environment of Muthupettai (Southeast coast 22 Zheng, Z., Zeng, W., Huang, Y., Yang, Z., Li, J., Cai, H & of India), Ph.D., Thesis, Annamalai University, India, 2002. Su, W., Detection of antitumor and antimicrobial activities in 6 Nair, P.V.R., Phosphorus fraction in Gulf of Mannar and marine organism associated actinomycetes isolated from the their relation to organic production, J. Mar. Biol. Ass., 7 Taiwan Strait, China, FEMS Microbiol. Lett, 188 (2000) (1983) 50-168. 87-91. 7 Vijayakumar, R., Muthukumar, C., Thajuddin, N., 23 Strickland J D H & Parsons T R, A practical handbook of sea Pannersevam, A & Saravanamuthu, R., Studies on the water analysis (Fisheries Research board of canada) 1972, diversity of actinomycestes in the Plak Strait region of Bay pp. 310. of Bengal, India. Actinomycetologica, 21 (2007) 59-65. 24 APHA, Standard methods for the examination of water and th 8 Das, S., Lyla, P & Ajmalkhan, S., Distribution and generic waste water, 18 edition: (American Public Health composition of culturable marine actinomycetes from the Association, Washington DC, USA) 1995. marine sediments of continental slope of Bay of Bengal, 25 El-Wakeel, S.K & Riley, J.P., 1956. The determination of Chinese. J. Oceanol. Linol., 26 (2008) 55-59. organic carbon in marine muds. J. Cons. Int. Explor. Mar., 9 Ghanem, N.B., Sabry, S. A., EI-Sherif, Z. M & EI-Ela, 22 (1956) 180-183. G.A.A., Isolation and enumeration of marine actinomycetes 26 Wentworth, C.K., A scale of grade and class terms for clastic from seawater and sediments in Alexandria, J. Gen. Appl. sediments, J. Geol., 30 (1992) 377-392. Microbiol., 46 (2000) 105-111. 27 Lindholm R, A practical approach to sedimentology, (Allen 10 Madrid, V.M., Taylor, G.T., Scraton, M.I & Chistoserdov, and Unwin, London) 1987, pp. 278. A.Y., Phylogenetic diversity of bacterial and archeal 28 Balagurunathan, R., Antagonistic actinomycetes from Indian communities in the anoxic zone of the Cariaco Basin, Appl. shallow sea sediments with reference to α, β unsaturated- Environ. Microbial., 67 (2001) 1663-1674. lactone type of antibiotic from Streptomyces gresiobrunneus 11 Rajkumar, J., Purification and characterization of Ph.D. Thesis, Annamalai University, India, 1992. commercially important enzymes from marine actinobacteria 29 Balasubramanian, R & Kannan, L., Physico-chemical isolated from the rhizosphere of seagrasses of the Gulf of characteristics of the coral reef environs of the Gulf of Mannar Biospherre Reserve, India, Ph.D. Thesis, Annamalai Mannar Biosphere Reserve, India, Int. J. Ecol. Environ. Sci, Univerisity, India, 2009. 31 (2005) 273-278. 12 Murugan, M., Srinivasan, M., Sivakumar, K., Sahu, M. K & 30 Okbah, M.A & EI-Gohary, S.E., Physical and chemical Kannan, L., Characterization of an actinomycetes isolated characteristics of Lake Edku water, Egypt, Mediter. Ma.r from the estuarine finfish, Mugil cephalus Lin, (1758) and its Sci., 3 (2002) 27–39. optimization for cellulose production, J. Sci. Indus. Res., 66 31 Sundaramanickam, A., Sivakumar, T., Kumaran, R., (2007) 388-393. Ammaiappan, V & Velappan, R.A., Comparative study of 13 Zobell C E, Marine Microbiology. In: A Monograph on physico-chemical investigation along parangipettai and Hydrobacteriology, edited by M.A, Waltham, (Chronica Cuddalore coast, J. Environ. Sci. Tech, 1 (2008)1-10. Botanica Company) 1946, pp. 240 pp. 32 Ramamoorthy, K., Plankton characteristics of the coral reef 14 Weyland, H., Actinomycetes in North Sea and Atlantic environment of the Gulf of Mannar Biosphere Reserve, India, Ocean sediments, Lett. Nature, 223 (1969) 858. Ph.D. Thesis, Annamalai University, India, 1998. 15 Walker, J.D. & Collwell, R.R., Factors affecting enumeration 33 Gothandaraman, N., Studies on Micro zooplankton, and isolation of actinomycetes from Chesapeake bay and Ph.D.Thesis, Annamalai University, India, 1993. Southeastern Atlantic Ocean sediments, Mar. Biol., 30 34 Seenivasan, R., Spectral reflectance properties of the Vellar (1975) 193-201. estuarine environment, southeast coast of India, M.Phil. 16 Okami Y & Okazaki T, Actinomycetes in marine Thesis, Annamalai University. India, 1998. environments, In Nocardia and Streptomycetes edited by M. 35 Gopinathan, C.P & Rodrigo, J.X., Investigations on primary Mordarski, W. Kurylowicz & W. Leljaszewicz (ed.), (Gustav production and related parameters in the inshore waters of Fisher Verlag and Stuttgart, Germany) 1978 pp.145-151. Tuticorin, J .Mar. Biol. Assoc. India, 33 (1991) 33-39. 17 Weyland, H., Distribution of actinomycetes on the sea floor, 36 Reddy, K. R., Jayaraju, N., Suryakumar, I & Srinivas, K., Zentral. Bakteriol. Supp., 11 (1981) 185-193. Tidal fluctuations in relation to certain physico-chemical GNANAM et. al: ACTINOBACTERIAL DENSITY IN THE CHENNAI COAST 265

parameters in Swarnamukhi river estuary, East Coast of 47 Martin, D.F., The carbon cycle, In: Marine Chemistry, edited India, Indian J. Mar Sci., 22 (1993) 232-234. by D.F.Martin, (Marcel Dekker, Inc, New York, USA) 1970, 37 Gouda, R & Panigrahy, R. C., Monthly variations of some pp. 267-367. hydrographic parameters in the Rushikulya estuary, east 48 Vinithkumar, N.V., Kumaresan, S., Manujsha, M & coast of India, Mahasagar Bull Nat. Ins. Oceangr, 26 (1993) Balasubramanian, T., Organic matter, nutrients and major 73-85. ions in the sediments of coral reefs and seagrass beds of Gulf 38 Islam, M.R., Hossain, M.K., Bahar, M.H & Ah, M.R., of Mannar Biosphere Reserve, South East Coast of India, Identification of the causal agent of leaf spot of betelnut an in Indian J. Mar. Sci, 28 (1999) 383-393. vitro evaluation of fungicides and plant extracts against it, 49 Dhevendaran, K., Maya, K., Natarajan, P., Studies on Pak. J. Biol. Sci., 7 (2004) 1758-1761. microbial ecology of south-west coast, (Proc Natl Sem 39 Shirodkar, P.V., Mesquita, A., Pradhan, U.K., Verlekar, Estuarine Management, Trivandrum) 1987, pp. 425-432. X.N., Babu, M.T. & Vethamony, P., Factor controlling 50 Laksmanaperumalsamy, P., Studies on actinomycetes with Physico-chemical characteristics in the coastal waters off special reference to antagonistic Streptomyces from sediment Mangalore -A multivariate approach, Environ. Res., 109 of Portonovo coastal zone, Ph.D. Thesis, Annamalai (2009) 245-257. University, India,1978. 40 Upadhayay, S., Physico-chemical characteristics of the 51 Adinarayana, G., Venkateshnan, M.R., Bapairaju, V.V., Mahanadi estuarine ecosystem, East Coast of India, Indian J Sujatha, P., Premkumar, J., Elliaich, P & Zeeck, A., .Mar. Sci., 17 (1998) 19-23. Cytotoxic compounds from the Marine actinobacterium, Rus 41 Anbazhagan, P., Hydrobiological and benthic ecology of J Bioorg.Chem., 52 (2007) 295-300. Kodiakarai coastal sanctuary (Southeast coast of India), 52 Vijayakumar, R., Muthukumar, C., Thajuddin, N., Ph.D. Thesis, Annamalai University, India, 1998. Pannersevam, A & Saravanamuthu, R., Studies on the 42 Kannabiran, E., Kannan, L., Purushothaman, A & diversity of actinomycestes in the Plak Strait region of Bay Thangaradjou, T., Physico-chemical and microbial of Bengal, India, Actinomycetologica, 21 (2007) 59-65. characteristics of coral reef environment of the Gulf of 53 Manivasagan, P., Sivakumar, K., Thangaradjou, T., Mannar Marine Biosphere Reserve, Indian J. Environ. Biol., Vijayalakshmi, S & Balasubramanian, T., Bacteial 29 (2008) 215-222. community and physico-chemical characteristics of 43 Gupta, A.K., Rathore, P., Kaur, N & Singh, R., Production, muthupettai mangrove environment, southeast coast of India, thermal stability and immobilization of Inulinase from J. Int. Dental. Med. Res., 2 (2009) 489-493. Fusarium oxysporum, J. Chem. Technol. Biotechnol., 47 54 Rivkin, R.B & Anderson, M.R., Inorganic nutrient limitation (1990) 245-257. of oceanic bacterioplankton, Limnol. Oceanogr., 42 (1997) 44 Mohamed Abubaker Sithik, A., Thirumaran, G., Arumugam, 730-740. R., Ragupathi Raja Kannan, R & Anantharaman, P., Physico- 55 Shiah, F., Ducklow, H.W., Temperature regulation of Chemical Parameters of Holy Places Agnitheertham and heterotrophic bacterioplankton abundance, production, and Kothandaramar Temple; Southeast Coast of India, American- specific growth rate in Chesapeake Bay, Limnol Oceanogr., Eurasian J. Sci. Reserch., 4 (2009) 108-116. 39 (1994) 1243-1258. 45 Rajasegar, M., Srinivasan, M & Ajmalkhan, S., Distribution 56 Sundararaj, V & Krishnamurthy, K., Nutrients and plankton, of sediment nutrients of Vellar estuary in relation to shrimp In: Backwater and Mangrove Environment, IN: N. Natarajan farming, Indian J. Mar. Sci., 31 (2002) 153-156. (ed.), Recent Resech. Esture. Biol., (1975) 273-390. 46 Davies, O.A & Abowei, J.F.N., Sediment quality of lower 57 Shirling, E. B & Gottlieb, D., Methods for characterization of reaches of Okpoka creek, Niger delta, Nigeria Euro. J. Streptomycetes species. Int. J. System. Bacteriol., 16 (1966) Scient. Res., 26 (2009) 437-442. 313-340.