ABSTRACT
ABSTRACT Organic compost from biomass residues constitutes a viable alternative for partial or total replacement of mineral fertilizers for growing vegetables. This study evaluated the effects of compost on the water quality of a stream used mainly for irrigation of agricultural crops cultivated in nearby soil that has been treated with organic compost produced by carcasses, animal and vegetable waste for the last ten years. We sampled water biannually for two years, 2013 and 2014, from five locations along the stream. Physical variables and some chemical variables were analyzed. We also analyzed the total number of coliforms (Escherichia coli). Bacterial populations were compared by carbon substrate consumption. Total phosphorus contents in the samples from 2014 exceeded 0.1 mg L-1. The concentrations of other chemical species analyzed and the results for the physical variables were in accordance with the expected values compared with national and international water quality standards. The environment showed differential carbon source consumption and a high diversity of microorganisms, but our results did not show any evidence that the applied compost is changing the microbial population or its metabolic activity. This study shows that the use of the organic compost in agricultural areas seen does not negatively influence the quality of surface water in the study area. These results are important because the process of composting animal and vegetable waste and the use of compost obtained can be an alternative sustainable for adequate destination of these wastes.
RESUMO Composto orgânico produzido a partir de biomassa residual constitui uma alternativa viável para a substituição parcial ou total de fertilizantes minerais no cultivo de hortaliças. Neste estudo foram avaliados os efeitos do composto, sobre a qualidade da água de um córrego, usado principalmente para a irrigação de culturas agrícolas cultivadas em solo nas proximidades, tratado nos últimos dez anos com composto orgânico produzido a partir de carcaças, resíduos animais e vegetais. Amostras de água foram coletadas semestralmente, em 2013 e 2014, em cinco pontos ao longo do córrego. Foram analisadas variáveis físicas, algumas variáveis químicas e o número total de coliformes (Escherichia coli). As populações bacterianas foram comparadas pelo consumo de substratos de carbono. Os teores de fósforo total nas amostras de 2014 ultrapassaram 0,1 mg L-1. As concentrações das demais espécies químicas analisadas e os resultados para as variáveis fisicas ficaram de acordo com valores estabelecidos em normas nacionais e internacionais de qualidade de água. O ambiente mostrou consumo diferencial de fontes de carbono e grande diversidade de micro-organismos, mas os resultados não mostraram qualquer evidência de que o composto aplicado seja o fator responsável pela alteração da população microbiana ou sua atividade metabólica. Este estudo mostra que o uso do composto orgânico em áreas agrícolas parece não influenciar negativamente a qualidade da água superficial na área estudada. Estes resultados são importantes porque o processo de compostagem de resíduos animais e vegetais e o uso do composto obtido podem ser uma alternativa sustentável para o destino adequado desses resíduos.
ABSTRACT
Objective To detect the changes of microbial community functional diversity of corpses with different postmortem interval(PMI)and to evaluate forensic application value for estimating PMI. Methods The cultivation of microbial community from the anal swabs of aSusscrofaand a human corpse placed in field environment from 0 to 240 h after death was performed using the Biolog-Eco Mi-croplate and the variations of the absorbance values were also monitored. Combined with the technology of forensic pathology and flies succession, the metabolic characteristics and changes of microbial commu-nity on the decomposed corpse under natural environment were also observed.Results The diversity of microbial metabolism function was found to be negatively correlated with the number of maggots in the corpses. The freezing processing had the greatest impact on average well color development value at 0 h and the impact almost disappeared after 48 h. The diversity of microbial metabolism of the samples be-came relatively unstable after 192 h. The principal component analysis showed that 31 carbon sources could be consolidated for 5 principal components(accumulative contribution ratio >90%). The carbon source tsquare-analysis showed thatN-acetyl-D-glucosamine andL-serine were the dominant carbon sources for estimating the PMI(0=240 h)of theSusscrofaand human corpse.Conclusion The Biolog-Eco method can be used to reveal the metabolic differences of the carbon resources utilization of the microbial community on the corpses during 0-240 h after death, which could provide a new basis for estimating the PMI.
ABSTRACT
OBJECTIVES@#To detect the changes of microbial community functional diversity of corpses with different postmortem interval （PMI） and to evaluate forensic application value for estimating PMI.@*METHODS@#The cultivation of microbial community from the anal swabs of a Sus scrofa and a human corpse placed in field environment from 0 to 240 h after death was performed using the Biolog-Eco Microplate and the variations of the absorbance values were also monitored. Combined with the technology of forensic pathology and flies succession, the metabolic characteristics and changes of microbial community on the decomposed corpse under natural environment were also observed.@*RESULTS@#The diversity of microbial metabolism function was found to be negatively correlated with the number of maggots in the corpses. The freezing processing had the greatest impact on average well color development value at 0 h and the impact almost disappeared after 48 h. The diversity of microbial metabolism of the samples became relatively unstable after 192 h. The principal component analysis showed that 31 carbon sources could be consolidated for 5 principal components （accumulative contribution ratio >90%）.The carbon source tsquare-analysis showed that N-acetyl-D-glucosamine and L-serine were the dominant carbon sources for estimating the PMI （0=240 h） of the Sus scrofa and human corpse.@*CONCLUSIONS@#The Biolog-Eco method can be used to reveal the metabolic differences of the carbon resources utilization of the microbial community on the corpses during 0-240 h after death, which could provide a new basis for estimating the PMI.
Subject(s)
Humans , Biodiversity , Cadaver , Carbon , Postmortem Changes , Principal Component Analysis , Soil Microbiology , Time FactorsABSTRACT
Biolog EcoPlateTM is a mainstream approach of studying community-level physiological profiles of microbes. To correct misunderstanding and insufficiency of experimental result explanation, we announced an amendment of information extraction of Biolog EcoPlateTM, which included two parts: (1) carbon substrates assortment sheets based on microbial physiological metabolism and ecological function, providing referrence and index for researchers; (2) illustration of how to use assorment sheet and ordination method to find out more information, guiding by environmental concentration principle.