Prospecting for sludge bacteria from a poultry slaughterhouse, with potential for degrading organic substances

Abstract

The sludge produced in wastewater treatment plants of slaughterhouses is a rich source of chemical, organic, and microbiological constituents that can be biotechnologically exploited. The purpose of this study was to (i) conduct a chemical analysis of the sludge, and (ii) isolate, quantify, and describe the amylolytic, cellulolytic, ligninolytic, proteolytic, and keratinolytic bacteria in the sludge. Sludge samples were collected at the wastewater treatment plant of the Francap SA poultry company. The nutrient contents, C/N ratio, and pH were determined. For the bacterial count, 10 g sludge was diluted in 90 mL saline solution, which was serially diluted to 10 -12 . Aliquots of 100 µL of each dilution were transferred to selective media for isolation of bacteria that degrade organic substances. The colony-forming units were determined for each culture medium. Individual colonies were purified and characterized morphologically. The sludge contained 9.5, 1.21, and 0.45 dag kg -1 of N, P, and K, respectively. Fiftytwo isolates were purified and characterized, with 2.11 × 10 12 to 9.55 ×10 15 colony-forming units per g sludge. In conclusion, the sludge generated in poultry slaughterhouse wastewater treatment plants is a rich source of organo-mineral constituents and bacteria with biotechnological potential for degrading organic substances. Key words: Agricultural microbiology. Organic matter. Solid waste. ResumoOs lodos produzidos nas estações de tratamento de efluentes de abatedouros são uma fonte de riqueza química, orgânica e microbiológica que precisa ser explorada biotecnologicamente. Objetivou-se neste estudo: (i) realizar a caracterização química do lodo e (ii) isolar, quantificar e caracterizar bactérias amilolíticas, celulolíticas, ligninolíticas, proteolíticas e queratinolíticas do lodo. Amostras de lodo foram coletadas na estação de tratamento de efluentes da empresa avícola FRANCAP S.A. Foram determinados os teores de nutrientes, a relação C/N e o pH. Para a quantificação bacteriana, 10 g de lodo foram diluídos em 90 mL de solução salina e dela, realizaram-se diluições seriadas até 10 -12 . Alíquotas de 100 µL de cada diluição foram transferidas aos meios seletivos para isolamento de bactérias degradadoras de substâncias orgânicas. Determinaram-se as unidades formadoras de colônia para cada meio de cultivo. Colônias individuais foram purificadas e caracterizadas morfologicamente. O lodo apresentou teores de N, P e K, de 9,5, 1,21 e 0,45 dag kg -1 , respectivamente. Foram purificados e caracterizados 52 isolados, as unidades formadoras de colônia variaram entre 2,11 x 10 12 a 9,55 x 10 15. Conclui-se que os lodos gerados nas estações de tratamento de efluentes de abatedouro de aves são uma fonte de riqueza organomineral, além de apresentar bactérias com potencial biotecnológico de degradar substâncias orgânicas. Palavras-chave: Matéria orgânica. Microbiologia agrícola. Resíduos sólidos.

Selection of diazotrophic bacteria isolated from wastewater treatment plant sludge at a poultry slaughterhouse for their effect on maize plants

“…The trays were maintained in a bacteriological incubator at 30 °C for seven days. The resulting colonies were characterized based on the cell characteristics (shape and gram staining) and the characteristics of the colonies (shape, color, size, elevation, edge, surface, and mucus) (Perin, 2003;Lozada et al, 2017). Each bacterial isolate was named by the following scheme: UFV L-ABC, in which UFV = Federal University of Viçosa; L = sludge; A = isolation culture medium (1 = JMV, 2 = JMVL, 3 = NFb, 4 = JNFb, 5 = LGI, 6 = LGI-P); B = dilution; and C = number of the isolate in the collection.…”

“…This study demonstrated the colonization capacity of diazotrophic bacteria isolated from environments of residues such as treated sludge from a poultry slaughterhouse. This sludge can be applied to environmental restoration processes and as raw material for manufacturing substrates and biofertilizer (Santos et al, 2014), and can be exploited as a source of microbial diversity for studies of bacteria with potential for degrading organic substances (Lozada et al, 2017) and plant growthpromoting bacteria. In conclusion, bacterial isolates from sludge of poultry slaughterhouses, in particular UFVL-162, UFVL-163, and UFVL-164, promote the growth and development of maize plants.…”