Chrysomya megacephala larvae feeding favourably influences manure microbiome, heavy metal stability and greenhouse gas emissions

Abstract

Summary Chrysomya megacephala is a saprophagous fly whose larvae can compost manure and yield biomass and bio‐fertilizer simultaneously. However, there are concerns for the safety of the composting system, that is risk of diseases spread by way of manure pathogens, residue of harmful metals and emission of greenhouse gases. Microbiota analysis and heavy metal speciation by European Communities Bureau of Reference were evaluated in raw, C. megacephala‐composted and natural stacked swine manure to survey pathogenic bacterial changes and mobility of lead and cadmium in manure after C. megacephala feeding; the emission rate of CH4 and N2O from manure during C. megacephala composting and natural stacking was also measured. C. megacephala composting altered manure microbiota, reduced the risk of pathogenic bacteria and maintained the stability, and microbiota changes might be associated with heavy metal fractions, especially in Pseudomonas and Prevotella. In addition, C. megacephala‐composting significantly reduced the emission rate of CH4 and N2O in comparing with natural stacking situation and the first two days should be the crucial period for CH4 and N2O emission measurement for manure treatment by C. megacephala. Moreover, OTU26 and Betaproteobacteria were changed after C. megacephala composting which might play a role in emission of CH4 and N2O, respectively.

Potentials and Limitations of the Bioconversion of Animal Manure Using Fly Larvae

“…Iwasa et al [74] observed 66 and 87% reductions in cumulative CH 4 and N 2 O emissions from cattle manure using Neomyia cornicina larvae. Similar results were obtained by Wang et al [182], who found that Chrysomya megacephala larvae can reduce by 58 and 66% of CH 4 and N 2 O emissions, respectively, from swine manure. Moreover, depending on the humidity, H. illucens larvae may reduce by 72.6-99.9% and 99.6-99.9% of CH 4 and N 2 O, respectively, compared to conventional composting [27].…”

“…Different studies reveal the ability of H. illucens and M. domestica larvae to reduce microorganisms on different substrates [38,87,89,102,124,179,197,198]. In this way, Wang et al [182] associated the reductions of CH 4 and N 2 O emissions from swine manure to the effect of C. megacephala larvae on reducing the abundance of methanogenic bacteria (Methanogens, Methanomassiliicoccaceae, Methanobrevibacter) and increased betaproteobacteria after the bioconversion process.…”

Molecular Identification and Species Richness of Flies (Diptera) and Their Associated Bovidae Hosts at Cattle Farms in Selangor, Malaysia

“…(besides Musca spp.) on Ladang UPM farm was due to the behaviour of this species which sought cattle dung as its preferred food source, as well as its breeding site (Wang et al, 2018). Infestation of fly larvae in live animals can cause myiasis, leading to tissue necrosis in cattle (Ferraz et al, 2010), which was not recorded in our study area.…”

Total Arsenic, pH, and Sulfate Are the Main Environmental Factors Affecting the Microbial Ecology of the Water and Sediments in Hulun Lake, China

“…We speculate that this may be related to the presence of more sulfides in the sediments. Pseudomonas plays an important role in processing heavy metals ( Zhang et al, 2017 ; Wang X. et al, 2018 ). These microorganisms also play an important ecological role in our co-occurrence network.…”