Growth Assessment of Microorganisms in Vermicomposting of Municipal Wastes Materials in Different Days
Abstract
In India over population, migrate village to town, various industries development, agricultural and municipal wastes have release to dumping of waste materials caused a serious causes to the environment. India enormous quantities of disposable organic wastes materials like municipal solid waste (MSW) rich in plant nutrients were presented. The macro and micro nutrients are available more in MSW, it is not properly decomposed (or) vermicomposting. MSW can’t be eaten directly by earthworms due to it bad smell, heavy metals, insects; water leachate to organic wastes etc. So the organic wastes such as dairy farm waste – cowdung (CD) and sugar industrial waste - pressmud (PM) with clay soil high nutritive content were mixed in equal ratio and used as bedding material (BM). The experimental bedding materials were prepared on dry weight basis by mixing the MSW + BM in the following percentage: T1 – 20% BM + 80% MSW, T2 – 40% BM + 60% MSW, T3 – 60% BM + 40% MSW, T4 – 80% BM + 20% MSW, C1 Control (BM alone) were also maintained separately. The microbial populations (bacteria, fungi and actinomycetes) were enumerated in the samples of 0 (Initial day), 15, 30, 45 and 60 days. The quantity of microbial population in the worm worked compost (vermicomposts) has significantly increased than worm unworked mixture. Microbial population was observed more in the vermicomposts of E. eugeniae than the L. mauritii. It could be due to the higher feeding rate, prolific breeding ability, suitable environment and multiplication of microbes while passing through the gut of worms and optimal moisture and activity of microbes.
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Introduction
Vermicomposting process, when organic matter passes through the worms gut it undergoes physical, chemical and biochemical changes by the combined effect of earthworm and microbial enzymatic activities. The role of microbial activity in the gut as well as in the casts is very essential for the degradation of organic waste and release of nutrients to plants (James, 1991). Vermicomposts have large particulate surface areas that provide many micro sites for microbial activity and for the strong retention of nutrients (Shi-wei and Fu-Zhen, 1991).
Vermicomposts are rich in microbial populations and diversity, particularly fungi, bacteria and actinomycetes (Edwards, 1998). Garcia-Gil et al. (2000) reported that the increase of microbial biomass in this long-term experiment with the organic amendments is mainly due to the microbial biomass contained in the organic residues and the addition of substrate-C, which stimulates the indigenous soil micro-biota, as confirmed by present analysis.
Dominguez (2004) suggested that vermicomposting is a combined operation of earthworm and microorganisms in which the earthworm fragments and homogenize the ingested material through muscular action of their foregut and also adds mucus and enzymes to ingested material and thereby increases the surface area for microbial action while, microorganisms perform the biochemical degradation of waste material providing some extra – cellular enzymes required for organic waste decomposition with the worm’s gut. Moreover, this biological mutuality caused C loss in the form of CO2 from the substrates during the decomposition of organic waste.
Tripathi and Bhardwaj (2004b) reported that various organisms are involved in the composting process which includes microorganisms like bacteria, fungi and worms.Suthar (2008b) stated that the microbial population increases during vermicomposting of cowdung.
Haritha Devi et al. (2009) reported that the enhanced microbial activity accelerated the decomposition process leading to humification, thus oxidizing unstable organic matter to stable form. During the passage through the gut of earthworms the surviving microorganisms are voided along with cast. Unfortunately, the comparative potentiality of Lampito mauritii and Eudrilus eugeniae for municipal solid waste (MSW) management has not been carried out. Many aspects of earthworm – microbial interaction require further study including selection, multiplication, feeding (Review: Curry and Schmidt, 2007). The objective of the present study was to test the role of L. mauritii and E. eugeniae on the population kinetics of bacteria, fungi and actinomycetes during vermicomposting of MSW.
Conclusion
The vermicomposts of L. mauritii show highest population of bacteria, fungi actinomycetes in T4 whereas the maximum numbers of colonies of microorganisms (bacteria, fungi and actinomycetes) were found T7 (vermicompost made by E. eugeniae). The control, vermicomposts of both earthworms show second place in the population of microbes.
The increased microbial population was observed in all experimental and control vermicomposts more than initial (0-day). The maximum microbial population was noted in the worm worked composts of T4 (L. mauritii) and T7 (E. Eugeniae).
Vermicomposting process, when organic matter passes through the worms gut it undergoes physical, chemical and biochemical changes by the combined effect of earthworm and microbial enzymatic activities. The role of microbial activity in the gut as well as in the casts is very essential for the degradation of organic waste and release of nutrients to plants (James, 1991). The size of microbial population in worm casts is mainly depends on the type and quality of ingested soil and plant materials (Edwards and Bohlen, 1996).
Earthworms are mainly responsible for fragmentation and conditioning of the substrate, increasing surface area for microbial activity and significantly altering biological activity of the process (Dominguez, 2004). Munnoli et al. (2010) reported that the earthworms are considered as natural bioreactors which proliferate along with other microorganisms and provide required conditions for the biodegradation of wastes.
In the present study the population of bacteria, fungi and actinomycetes are found to increase from the initial, but highest increase among the vermicomposts of L. mauritii was found in T4 and in the vermicomposts of E. eugeniae was found in T7. It might be due to the optimal moisture, nutrient rich substrate concentration ideally suited for better feeding and multiplication of microbes as suggested by Parthasarathi (2002). John Paul et al. (2011); Ananthakrishnasamy (2013) mentioned that the higher CFU of microbes in the vermicomposts from MSW are due to higher proportion of cowdung which is supporting our present investigation in which we have observed higher microbial population in T4 by L. mauritii whereas in T7 by E. eugeniae due to the difference in palatability, gut enzymes and worm gut micro flora.