Interaksi Bakteri patogen Tumbuhan dengan Lingkungan Oleh: Irda Safni

Jenis interaksi Interaksi bakteri dengan bakteri lain Interaksi bakteri dengan jamur Interaksi bakteri dengan virus Interaksi bakteri dengan nematoda Interaksi bakteri dengan serangga & organisme makro lainnya

The inter- and intra-relationships between various microorganisms which can include both positive (like SYMBIOSIS) and negative (like ANTIBIOSIS) interactions. Examples include virus - bacteria and bacteria - bacteria. The consortium may be in intermitent,cyclic or permanent. These are ubiquitous, diverse and critically important in the function of any biological community.

These includes- oNeutralism oMutualism oCommensalism oParasitism oCooperation oPredation oAmensalism oCompetition

Neutralisme Microorganisms have no effect on each other. Observed in natural communities if- Culture density is low. Nutrient level is high. Each culture has distinct requirements.

Mutualisme rgida) An obligatory relationship. Highly specific. They operate as a single organism. Both organisms benefit. For Eeg.Diatom(Climacodium) and cyanobacteria(Epithemia tu Lichen-Fungi with Cyanobacteria. rgida)

Lichen symbiosis Lichens are associations of fungus (host) with photosynthetic alga or cyanobacteria (symbiont). Fungus (ectosymbiont) provides minerals by releasing lichen acids that dissolve substrate, release small amounts of P, S, other minerals, and obtains water from air. The endosymbiont carries out photosynthesis, converts CO2 to organic matter to feed itself and fungus host. Resulting symbiotic organisms can grow attached to rocks, tree trunks, other unlikely habitats

Usnea (fructicose)) Xanthoparmelia substrigosa (foliose) The endosymbionts are visible as round bodies within the cytoplasm. endosymbionts are important in fixing atmospheric nitrogen for use by the cells. Clim

Bekerja sama (Cooperation) Positive but not obligatery symbiosis Can be separated from one another. For eg-Desulfovibrio & Chromatium,Cellulomonas & Azotobactor.

Komensalisme One partner(commensal) benefits. while other(host) remains unaffected. – Common among organisms, not obligatory – Unidirectional – Usually, unaffected population modifies the environment in a way that other population benefits. For eg-during Nitrification ,oxidation of NH4+ ions get convert into nitrate. Nitrosomonas convert NH4+ Ions to nitrite and nitrobacter oxidise nitrite into nitrate.

Parasitisme One speices is dependent on a another for nutrition and growth. oIn it, one organism is benefitted and other is harmed. Closly related to predation. oCoexistence between host and parasite. For eg-Viruses are the highly specialized intracellular parasites,generally kill the host.

cell.Myxococcus xanthus and E.coli. Microbial parasite may kill the host or can have stable relationship without killing the host.(lysogeny provirus is carried on host chromosome). Pathogenic parasite may attack and kill the plant or animal host. Obligate parasite Treponema pallidum(syphilis),Rickettsia(Rockey mountain fever) can’t grow without an appropriate host.

Pemangsaan (Predatory) It involves predator species which target other microbe for material to survive. Predator attacks and kills its prey. They can be obligate or facultative. Members of predatory bacteria are known as ‘Bdellovibrio and like organisms’(BALO).They can be epibiotic,periplasmic,cytoplasmic. For eg- Bdellovibrio-E.coli interaction (Vampirococcus,Daptobacter both attack Chromatium.

Antibiotic production

AMENSALISME Focuses on exclusion of an organism from growing on a specific site to prevent the utilization of limiting nutrients. Unidirectional process based on the release of a specific compound by one organism that has negative effect on another. Product of one impact another i.e one species remains uneffected while other is harmed. For eg- microbial production of antibiotics that can inhibits or kill another.penicillin by fungi inhibit a type of cell wall found

only in bacteria. Bacteriocins-kill the strains of closely related species by generating holes in plasma membrane Metabolic end products.

KOMPETISI It arises when different organisms within population try to acquire same resources. Both the species are harmed. Competiton within the species or among different species can be attributed to availibility of Nitrogen source,carbon source,electron donors,electron accepter,vitamins,light,water. Competition may result in exclusion of other species or the establishment of a steady state where multiple species coexist.

Eg- In aquatic environment where extensive phototrophic activity results in blooms of single species of diatoms or cyanobacteria. Thermophilic springs chemolithotrophic organisms are selected. Lactic acid fermentation of food. Large intestine of animals,a single species doesn’t dominate but a mixed population coexist.

Interaksi Bakteri-Bakteri Hubungan Intraspesifik (sama spesies) Hubungan interspesifik (beda spesies)  untuk pengendalian hayati

Interaksi Bakteri-Jamur Antagonisme: hubungan antar patogen yang berbeda spesies, yang sebagian atau seluruhnya menghambat/membunuh patogen lain Contoh. Penicillium sp. menghambat pertumbuhan bakteri patogen. 2. Komensalisme: hubungan antar patogen yang berbeda spesies yang mengikuti serangan/infeksi patogen lain. Contoh. Infeksi busuk basah, biasanya didahului oleh infeksi jamur yang menyebabkan busuk kering/nekrosis 3. Sinergisme: parasitisme yang terjadi bersama-sama dalam 1 inang oleh 2 patogen yang menghasilkan gejala/pengaruh lain yang lebih besar dari pengaruh patogen jika bekerja sendiri-sendiri. Contoh. Ralstonia solanacearum & Phytophtora sp.

Interaksi Bakteri-Virus 3 Bacteriophages or phages are (bacterial viruses) that infect prokaryotes Ernest Hanbury Hankin in 1896 found in Ganges and Yamuna rivers in India and Pass through a very fine porcelain filter. Frederick Twort In 1915 Discovered Bacteriophage Felix d'Herelle Independently discovered again 1917 Image: Prescott’s Microbiology Image: Wikipedia

Bacteriophage as Biocontrol Phage Therapy Reduction of Colonization Animal Biosanitation Disinfection of equipments, contact surfaces Food Industry Biocontrol Carcasses, Raw material Food Industry Biopreservation Storage and preservation Final Product

Interaksi Bakteri-Nematoda Kebanyakan hubungan sinergisme – nematoda sebagai patogen primer Nematoda membantu penetrai bakteri melalui luka-luka yang dibuatnya. Nematoda mempengaruhi fisiologi tanaman, sehingga tanaman menjadi lebih peka terhadap infeksi bakteri. Contoh. Interaksi nematoda Puru Akar dengan bakteri layu

Ada 2 hubungan penting: 1). Obligatory relationships (hubungan yang wajib) Satu patogen bergantung pada patogen lain secara langsung, sehingga muncul gejala penyakit jika kedua patogen hadir bersama-sama. 2). Fortious relationships (hubungan secara tiba-tiba) Masing-masing patogen bertindak secara sendiri-sendiri dan tidak langsung dipengaruhin patogen tersebut. Sehingga nematoda hanya meningkatkan kejadian dan keparahan penyakit, bukan menimbulkan gejala penyakit.

Interaksi Bakteri-Serangga & organisme makro lainnya Parasitisme: bakteri memarasit serangga Contoh: Bacillus thuringiensis 2. Sinergisme & simbiosis mutualisme - Gigitan serangga menjadi lubang penetrasi bakteri - Bakteri melekat pada badan serangga menjadi vektor yang membantu penyebaran. - Serangga memberi perlindungan selama kondisi tidak baik bagi bakteri, lalu bakteri memberi vitamin/enzim-enzim yang diperlukan serangga, atau mempengaruhi tanaman sehingga tersedia banyak nitrogen bagi serangga. Contoh. Lalat buah pada apel - lalat mempunyai organ khusus (sejenis kantung) pada dinding oviductnya sebagai tempat bakteri.