Role of Microbes on Biodegration
POTENTIAL ROLE OF BENEFICIAL MICROBES ON BIODEGRATION OF AGROCHEMICALS IN SOIL
Pesticide at present is an indispensable tool to increasing the yield and to protect the economically important crops from pest, insects, fungi, nematode and weeds. Fungicides, herbicides, insecticides, nematicides, rodenticides, fumigants, disinfectants, wood preservatives, and antifoliants are examples of pesticides. Generally, Herbicides are unavoidable in the present scenario in latest agriculture. Weeds are to be eradicated meanwhile the serious intention on soil fertility could be improved via degradation of heavy metals and herbicides by beneficial soil microbes population. For which, the effective and selective biological should be built up in soil for ease degradation of herbicides. Biodegradation of pesticide by bacteria, fungi, algae and other organisms is ecofriendly, most efficient and economical method of detoxification. It uses naturally occurring bacteria, fungi, algae, plants to degrade or detoxify substances hazardous to human health or environment (Murali et al., 2014). Many of the studies on the interactions of herbicides and soil microorganisms have been concerned with herbicide persistence. They have dealt with the breakdown of herbicidal compounds by soil microorganisms and in this respect bacteria (Pseudomonas and Bacillus subtilis) and fungi (Trichoderma and VAM) appear to be more effective.
Role of Pseudomonas fluorescence (Biocure B) & Bacillus subtilis (Sting):
- Pseudomonas Improves yield by improving plant health through controlling the disease causing pathogens (root rot, root wilt, seedling rot and collar rot).
- An ecofriendly and maintains the ecological balance.
- Does not create resistance resurgence or residue problems.
- Forms a good molecule for use in integrated disease management programs.
- Acid producing bacterial organism such as phosphate solubilizing bacteria Pseudomonas influence on soil environment in the agriculture field and heavy metal contaminated soil may change the soil physical chemical nature of the soil after treating the soil with this beneficial organism.
- By producing organic acids it is able to solubilize, mobilize, and modify the hard, undissolved, unavailable forms of minerals in to the easily available and high soluble nature.
- Bacillus subtilis is a naturally occurring beneficial bacteria capable of protecting plants from disease causing pathogens (blight disease, powdery and downy mildew, Rust).
- Does not create resistance, resurgence and residues problem.
- By production of certain enzymes and secondary metabolites, they degrade the heavy metals and herbicides apply in the soil.
- Bacillus subtilis (Bs-15) could be used to alleviate contamination from glyphosate-containing herbicides, increasing the microbial functional diversity in glyphosate-contaminated soils and thus enhancing the bioremediation of glyphosate-contaminated soils (Yu et al 2015).
Supporting research findings:
Pseudomonas sp. and Klebsiella pneumoniae have been shown to possess hydrolytic enzymes that are capable of breaking down s-triazine herbicides, such as atrazine. Similarly, a number of enzymes such as oxygenases, hydroxylases, hydrolases and isomerases present in Pseudomonas and Alcaligenes sp. have been shown to degrade herbicide 2, 4-D (Mulbry and Kearney, 1991).
Enzymes are also involved in the degradation of pesticide compounds, both in the target organism, through intrinsic detoxification mechanisms and evolved metabolic resistance, and in the wider environment, via biodegradation by soil and water microorganisms (Shapir et al., 2007).
- fluorescens and Acetobacter sp. exhibited a high capacity to efficiently degrade glyphosate under the environmental conditions studied. Thus, the organisms can be exploited for biodegradation of glyphosate and should be studied for their ability to degrade other organophosphates (Moneke et al 2010).
Role of Trichoderma viride (Biocure B):
- Trichoderma controls the root diseases and several foliage diseases by mycoparasitism, production of antibiotics and etc.
- It triggers the production of phytohormones in the plant system for higher productivity by which it supports the plant growth.
- It suppresses the harmful fungal pathogens effectively and make the rhizosphere zone healthy.
Especially, oxidoreductases, laccase and peroxidases have prominent application in
removal of polyaromatic hydrocarbons (PAHs) contaminants either in fresh, marine
water or terrestrial (Balaji et al., 2013).