BI 330 MICROBIOLOGY MICROBIAL REPRODUCTION BY DR. MATHUROT CHAIHARN Programmed in Biotechnology, Faculty of Science, Maejo University, Chiang Mai, THAILAND Prokaryotes Domain Archaea Domain Eubacteria Kingdom Monera Prokaryotes Most abundant group Widely distributed Oldest organisms Domain Eukaryotes Organelles Plasma membrane Cell wall, if present, made up of polysaccharides Fungi : chitin Plants/Algae: cellulose or pectins Vertebrates: no cell wall Eukaryotes vs. Prokaryotes Prokaryotes Eukaryotes DNA DNA Nonmembrane, nucleiod Membrane, nucleus One circular Multiple chromosome chromosomes No histones Associated with histones Organelles Organelles Cell Walls: peptidoglycan Cell Walls Division Division Asexual Sexual: Meiosis Binary Fission Asexual: Mitosis Snapping Motility: Flagella whips Budding Motility: Flagella spins Domain Archaea Evolved from earliest cells Methanogens Largest group Use CO2 Extreme environment Halophiles Thermophiles Psychrophiles Acidophiles Alkaliphiles Eubacteria Prokaryotic Unicellular Shapes Vary in size Taxonomy: Bergey’s Manual of Systematic Bacteriology Low G+C Gram Positive High G+C Gram Positive Gram Negative Proteobacteria Nonpathogenic: environmental contributions Pathogenic Bacterial Shapes Result of Asexual Reproduction Binary Fission Cross wall divides Daughter cells +/- separate Snapping Division Inner cell wall divides Daughter cells hinged Budding Outgrowth of original cell Reproduction in Prokaryotes Binary fission Budding Conidiospores (actinomycetes) Fragmentation of filaments Budding Snapping Division Binary Fission Binary Fission Results Cocci Bacillus Pairs Separate Chains Pairs Tetrads Chains Cubes Clusters Bacterial Shapes Cocci: Pairs Division in one plane Diplococci Neisseria Cocci: Chains Division in 2 Planes Streptococcus Cocci: Tetrads Division in three planes Micrococcus Cocci: 8-cell group Divides in 3 planes Sarcina Cocci: Clusters Division in 3 planes Staphylococcus Cocci Summary Rods: Straight Escherichia coli Rods: Club-Shaped Corynebacterium Rods: Branching Actinomyces Rods: Comma form Vibrio Rods: Spore Formers Summary of Gram Negative Rod Summary of Gram Positive Rod Spiral Forms Bacterial Shapes Low G+C Gram Positive Organisms Rods Clostridia Mycoplasmas Bacillus Listeria Lactobacillus Cocci Streptococcus Enterococcus Staphylococcus High G+C Gram Positives Rods Corynebacterium Mycobacterium Corynebacterium Actinomycetes Actinomyces Nocardia Streptomyces Nocardia M. tb Gram Negative Alpha Proteobacteria Pathogenic Rickettsia Brucella Ehrlichia Ehrlichia Gram Negative Beta Proteobacteria Pathogenic Neisseria Bordetella Spirillum Burkholderia Gram Negative Gamma Proteobacteria Pathogenic Legionella Coxiella Pseudomonads Enterobacteriaceae E. coli Salmonella Shigella Proteus Yersinia Enterobacter Pseudomonas Serratia Gram Negative Epsilon Proteobacteria Pathogenic Campylobacter Helicobacter Helicobacter Campylobacter Other Bacteria Chlamydia Pathogenic Chlamydia Spirochetes Treponema [syphilis] Borrelia [Lyme ds] Borrelia Treponema Fungal Reproduction Fungi The Body of a Fungus Fungi exist mainly in the form of slender filaments (hyphae). Long chains of cells joined end-to-end divided by cross- walls (septa) Cytoplasm freely streams in hyphae Mycelium - mass of connected hyphae Grows through and penetrates substrate How Fungi Reproduce Each compartment of hypha can contain one, two or more nuclei Monokaryotic - Each compartment has a single nucleus Dikaryotic - Two distinct nuclei within each hyphae compartment How Fungi Reproduce Fungi are capable of both sexual and asexual reproduction. Fungi reproduce sexually after two hyphae of opposite mating type fuse. In some fungi fusion two haploid cells immediately results in diploid cell (2n) Basidiomycetes and ascomycetes have dikaryotic stage (1n + 1n) before parental nuclei fuse to form diploid nucleus Hyphal growth from spore Germinating spore Mycelium Mycelia have a huge surface area How Fungi Reproduce Spores most common means of reproduction May form from asexual or sexual processes Most often dispersed by wind but some spread by insects or other small animals Asexual Reproduction Special reproductive structures called spores or propagates The fungal spores always result from mitosis Described as mitospores Following are the types of spores produced in different groups of fungi: Zoospores Sporagiospore Chlamydospores Conidia Oidia Asexual spore Zoospores Sporagiospores Flagellated, motile spores Non-motile spores produced inside produced inside structures called structures called zoosporangia sporangia Do not have a cell wall Rhizopus and Mucor Produced in lower fungi Spores are dispersed such as Achyla and by wind Saprolegnia Asexual spore Chlamydospores Conidia Thick walled resting spores Non-motile spores which arise directly from hyphal produced singly or in cells. chains at the tip of the They store reserve food hypha branches Conidiophores Oidia Aspergillus Penicillium Spore like structures as breaking up of hypha cells Do not store reserve food Cannot survive under unfavourable conditions. Rhizopus sp. Asexual spore Four Major Groups of Fungi Four major groups Chytridiomycota Zygomycota Basidiomycota Ascomycota Sexual Reproduction Oomycetes produce gametangia Oogonium contains haploid oocytes produced by meioses Antheridia develop and produce haploid nuclei via meioses Nuclei migrate to oogonia across a fertilization tube developed by the oogonium to fertilize an oocyte. Their fusion produces diploid oospores Oospores germinate and produce coenocytic non-septate hyphae with many nuclei This life cycle is diploid Sexual Reproduction Chytrids Some have gametes which fuse (gametogamy). Similar in size (izogamy) or different size (anyzogamy). Oogamy : a bigger, non-motile oocyte and is fertilized by a motile gamete (oogamy) In some chytrids the gametangia fuse (gametangiogamy) and in others gametes fertilize gametangia Somatogamy : thalli of chitrids fuse Chytrids Sexual Reproduction Gametangia are the sexual reproduction of zygomycetes Compatible coenocytic hyphae with haploid nuclei develop gametangia, generally opposite to each other, and these gametangia fuse (gametangiogamy) The nuclei also fuse (karyogamy) and a thick walled, zygospore develops Zygomycota : Greek name of yoke (“zygos”), as the opposing gametangia The zygospore, is a resting zygote When the zygospore germinates, a sporangium developed from the hypha produces endogenous haploid mitospores. Development of Gametangia Gametangia in Fungi Sexual Reproduction Ascomycota refers to the sac-like structure (ascus) Produced ascospores (meiospores) The haploid nucleus migrates from the antheridium to the ascogonium Dikaryotic hyphae with two nuclei of different origin will develop in each segment Development of Ascus Mitotic cell division 1: Ascogonium, 2: Ascogenous hyphae; 3: Crozier; 4: Ascus initial; 5: Ascus with ascospores Ascomycota Yeasts Unicellular - most reproduction is asexual and takes place by cell fission or budding Ferment carbohydrates Basidiospore The hyphae developing from haploid basidiospores fuse (somatogamy) and produce dikarytic hyphae. The nuclei fuse (karyogamy), and the diploid nucleus undergoes meiotic division. The four haploid nuclei migrate into the developing basidiospores across the spore-holding sterigma. Development of Basidiospore 1: Clamp; 2: Nuclei; 3 Karyogamy; 4: Meiosis; 5: Vacuole; 6: Sterigma; 7: Basidiospore Mushroom and Basidiospore References Bacteria. (2008). In Encyclopædia Britannica. Retrieved September 22, 2008, from Encyclopædia Britannica Online: 'Instant Notes In Microbiology (1999) BIOS Scientific Publishers, J.Nicklin, K. Graeme-Cook, T.Paget & R. Killington‘ Hertman J, Kronstand JW, Taylor JW, Casselton L. (2007) Sex in Fungi : molecular determination and evolutionary implications. ASM Press. Xu J. (2004). The prevalence and evolution of sex in microorganisms. Genome 47: 775-780. Xu J. (2006). Microbial ecology in the age of genomics and metagenomics : concepts, tools and recent advances. Molecular Ecology 15: 1713-1731..