Isolation and characterization of cellulose degrading ability in Paenibacillus isolates from landfill leachate

Aims: Cellulases are enzymes that convert cellulose into glucose molecules, and are produced by various microorganisms in the environment. Due to their importance to the biofuel industry, there is a need to screen for more efficient varieties of cellulases. In this study, leachate samples from a landfill site were screened for cellulolytic bacteria. Methodology and results: Leachate samples obtained from a landfill collection pond were cultured in an enriched cellulose medium. Two cellulolytic isolates, designated MAEPY1 and MAEPY2, were isolated and further characterized. Phenotypic profiles and phylogenetic analyses using sequences of 16S rRNA, gyrB and whole genome suggested that these isolates are new strains of the Paenibacillus genera. The crude enzyme extracts from both isolates have cellulose degradation activity at approximately 0.1-0.2 IU/mg under working conditions of pH 6 and 55 °C. Assays using other lignocellulosic substrates showed that the crude enzyme extracts also have high xylan degradation activity. Conclusion, significance and impact of study: Paenibacillus sp. are known to produce multiple enzymes for lignocellulolytic degradation and the present results suggest that isolates described in this study, MAEPY1 and MAEPY2, are excellent candidates deserving further study as potential producers of efficient cellulases for use in industries associated with cellulosic biomass.

Incorporation by host tissue of two biomaterials used as repair of defects produced in abdominal wall of rats

PURPOSE: Biomaterials may be used as treatment of great abdominal wall defects to avoid tension during repair. In the present research we intended to investigate incorporation type by host tissue of membranes of microbial cellulose (MC), produced by the bacteria Zoogloea sp., and of polytetrafluoroethylene (ePTFE) in abdominal wall defects of rats. METHODS: Sixty male rats Wistar, anesthetized by ketamine (5mg/100g) and xylazine (2mg/100g), were submitted to a rectangular excision (2x3cm) of the abdominal wall, including fascia, muscles and peritoneum and further treated with implants of microbial cellulose (MC Group - 30 animals) or expanded polytetrafluoroethylene ( ePTFE Group- 30 animals). Each group was subdivided in 14th DPO, 28th DPO and 60th DPO Subgroups. RESULTS: Incorporation of biomaterials was observed by wrapping and infiltration by host tissue. It has been found that wrapping associated to infiltration of host connective tissue in implants of ePTFE were present in 100 percent of the observed samples, and this may be responsible for increase resistance to traction. Inversely, wrapping without host tissue infiltration was seen in 100 percent of examined specimens of MC implants. CONCLUSION: Wrapping and host tissue infiltration is seen only in ePTFE implants.

OBJETIVO: Biomateriais podem ser usados como tratamento de grandes defeitos da parede abdominal para evitar tensão durante reparo. Na presente pesquisa pretendeu-se investigar o tipo de incorporação pelo tecido do hospedeiro de membranas de celulose microbiana (CM), produzidas pela bactérias Zoogloea sp., e de politetrafluoretileno (PTFEe) em defeitos da parede abdominal de ratos. MÉTODOS: Sessenta ratos machos Wistar, anestesiados através de cetamina (5mg/100g) e xilazina (2mg/100g), foram submetidos a uma excisão retangular (2x3cm) da parede abdominal, incluindo fascia, músculos e peritoneum e posteriormente tratadas com implantes de celulose microbiana (Groupo CM - 30 animais) ou politetrafluoretileno (Grupo PTFEe - 30 animais). Cada grupo foi subdividido em Subgrupos14º DPO, 28º DPO e 60º DPO. RESULTADOS: Incorporação do biomaterial foi observada através de envoltório e infiltração pelo tecido do receptor. Foi encontrado que o envoltório associado à infiltração de tecido conjuntivo do hospedeiro em implantes de ePTFE estava presente em 100 por cento das amostras observadas, podendo ser responsável por aumento da resistência à tração. Inversamente, envoltório sem infiltração de tecido do hospedeiro foi visto em 100 por cento dos espécimes examinados nos implantes de CM. CONCLUSÕES: Pode-se ser concluído que o envoltório associado à infiltração de tecido do hospedeiro só é vista nos implantes de PTFEe.