Search

The present study aimed to isolate and select bacteria with cellulolytic capacity, having future application as inoculum in the fibrous organic waste composting. Five sampling environments were considered: organic agriculture (AO), conventional agriculture (AQ), forest (BM); sugarcane area (RC) and compost piles (AC). For bacterial isolation the nutrient agar medium was used changing the carbon source by cellulose. The main selection criterion of the bacterial isolates was the growth on above medium and its positive reaction to congo red test, showing clear zones around the colonies. The 93 bacterial isolates obtained were subjected to Gram staining, catalase test, presence of endospores and aerobically growth; having 70 bacteria Bacillus spp. like characteristics. Their cellulolytic activities were determined and 30 bacteria produced hydrolysis halo. Eight of these bacterial isolates were selected according to the largest halo production (AO-19, AO-28, AO-29, AQ-2, BM-7, RC-2, RC-6, CR-18) and their growth at different pH (3, 5, 7, 9) and temperatures (50 and 70 °C) were evaluated. The bacteria AO-19 showed higher hydrolysis halo with 12,33 mm and growth stability at different pH and temperature levels, for which its growth dynamic and amylolytic and pectinolytic capacity was determined. According to results the bacteria AO-19 has potential to be used as inoculum in composting. [ABSTRACT FROM AUTHOR]

Objective. To characterize probiotic lactic acid bacteria isolated from adult pig intestine as an alternative to antibiotics. Materials and methods. For isolation of lactic acid bacteria, samples of large intestine of 20 adult pigs were included. The characterization of biochemical and physiological parameters of the lactic acid bacteria (LAB) required an evaluation of the pH of the ferment, determination of organic acids by HPLC and detection of lactic acid isomers. Microbiological processes assessed the capacity of inhibiting the growth of pathogenic and antagonistic activity of probiotic antibiotic vs competitive interaction. We used API CH 50 test to identify the LAB supplemented with gas production, catalase activity and viability at different concentrations of bile salts and temperatures. Results. The analysis plan allowed selection of two isolates that were identified as: Lactobacillus plantarum 1 H1 y L. plantarum 1 H2. Microbiological testing showed that the lactic bacteria selected inhibited the enteropathogens Escherichia coli, Salmonella typhimurium and Clostridium perfringens. The biochemical tests were consistent with the genus Lactobacillus, showed the following profile: catalase negative, non- gas producing, producing isomers DL; resistant to bile salts and pH optimum for growth of 3.5 to 38°C. Conclusions. The two isolates of L. plantarum 1 were considered eligible for potential use as probiotics. Its use is recommended in addition to antibiotic therapy and the development of inoculum for use in food rations for weaned piglets, however, additional studies are needed to assess the direct effect of probiotics as a substitute for antibiotics in vivo. [ABSTRACT FROM AUTHOR]