RESUMO
Various carbon sources were evaluated for production of inulinase by yeast, Kluyveromyces marxianus MTCC 3995. Highest inulinase activity was observed with Dahlia extract (25.3 nkat mL-1) as carbon source. The enzyme activity was 1.4 folds higher than that observed in media containing pure chicory inulin (17.8 nkat mL-1). The yeast showed good growth on a simple medium containing dahlia extract (20% w/v) and yeast extract (2%w/v) as carbon and nitrogen source respectively, in 96 h. at 28°C and 120 rpm. Lowest inulinase yield (4.8 nkat mL-1) was seen in the medium containing glucose as C-source. Although varied inulinase levels were noticed on different C- sources, Inulinase: Sucrase (I/S) ratios were noticed to be similar. Among various protein sources tested, yeast extract was found to be the best source followed by beef extract (17.9 nkat mL-1) and peptone (13.8 nkat mL-1). The enzyme was optimally active at pH (4.0) and 50°C. TLC analysis of end product revealed that inulinase hydrolyzed inulin exclusively into fructose. Results suggest that the dahlia extract induced exoinulinase synthesis in Kluyveromyces marxianus and can be utilized as a potential substrate for inulinase production.
Assuntos
Estruturas Vegetais/enzimologia , Extratos Vegetais/análise , Frutose/análise , Inulina/análise , Inulina/isolamento & purificação , Kluyveromyces/isolamento & purificação , Leveduras/isolamento & purificação , Dahlia , Ativação Enzimática , MétodosRESUMO
Various carbon sources were evaluated for production of inulinase by yeast, Kluyveromyces marxianus MTCC 3995. Highest inulinase activity was observed with Dahlia extract (25.3 nkat mL(-1)) as carbon source. The enzyme activity was 1.4 folds higher than that observed in media containing pure chicory inulin (17.8 nkat mL(-1)). The yeast showed good growth on a simple medium containing dahlia extract (20% w/v) and yeast extract (2%w/v) as carbon and nitrogen source respectively, in 96 h. at 28°C and 120 rpm. Lowest inulinase yield (4.8 nkat mL(-1)) was seen in the medium containing glucose as C-source. Although varied inulinase levels were noticed on different C- sources, Inulinase: Sucrase (I/S) ratios were noticed to be similar. Among various protein sources tested, yeast extract was found to be the best source followed by beef extract (17.9 nkat mL(-1)) and peptone (13.8 nkat mL(-1)). The enzyme was optimally active at pH (4.0) and 50°C. TLC analysis of end product revealed that inulinase hydrolyzed inulin exclusively into fructose. Results suggest that the dahlia extract induced exoinulinase synthesis in Kluyveromyces marxianus and can be utilized as a potential substrate for inulinase production.
RESUMO
Various carbon sources were evaluated for production of inulinase by yeast, Kluyveromyces marxianus MTCC 3995. Highest inulinase activity was observed with Dahlia extract (25.3 nkat mL-1) as carbon source. The enzyme activity was 1.4 folds higher than that observed in media containing pure chicory inulin (17.8 nkat mL-1). The yeast showed good growth on a simple medium containing dahlia extract (20% w/v) and yeast extract (2%w/v) as carbon and nitrogen source respectively, in 96 h. at 28°C and 120 rpm. Lowest inulinase yield (4.8 nkat mL-1) was seen in the medium containing glucose as C-source. Although varied inulinase levels were noticed on different C- sources, Inulinase: Sucrase (I/S) ratios were noticed to be similar. Among various protein sources tested, yeast extract was found to be the best source followed by beef extract (17.9 nkat mL-1) and peptone (13.8 nkat mL-1). The enzyme was optimally active at pH (4.0) and 50°C. TLC analysis of end product revealed that inulinase hydrolyzed inulin exclusively into fructose. Results suggest that the dahlia extract induced exoinulinase synthesis in Kluyveromyces marxianus and can be utilized as a potential substrate for inulinase production.
RESUMO
Feather waste is generated in large amounts as a by-product of commercial poultry processing. This residue is almost pure keratin, which is not easily degradable by common proteolytic enzymes. Eight strains of Bacillus, isolated from decomposing feathers were tested for the hydrolysis of feather wastes in the laboratory. Among these strains, Bacillus cereus KB043 was the best feather degrading organism when grown on basal medium containing 1 percent hen feather as sole source of carbon and nitrogen. It caused 78.16 ± 0.4 percent degradation with a significant release of soluble protein (1206.15 ± 14.7 µg mL-1) and cysteine (20.63 ± 0.4 µg mL-1) in the cultivation fluid. The strain also showed the highest level of keratinase activity (39.10 ± 0.4 U mL-1). These data indicates that the Bacillus cereus KB043 could be useful in management of poultry wastes.
Assuntos
Animais , Bacillus cereus , Bacillus/enzimologia , Bacillus/isolamento & purificação , Ativação Enzimática , Peptídeo Hidrolases/análise , Plumas/enzimologia , Queratinas/análise , Biodegradação Ambiental , Aves , MétodosRESUMO
Feather waste is generated in large amounts as a by-product of commercial poultry processing. This residue is almost pure keratin, which is not easily degradable by common proteolytic enzymes. Eight strains of Bacillus, isolated from decomposing feathers were tested for the hydrolysis of feather wastes in the laboratory. Among these strains, Bacillus cereus KB043 was the best feather degrading organism when grown on basal medium containing 1% hen feather as sole source of carbon and nitrogen. It caused 78.16 ± 0.4 % degradation with a significant release of soluble protein (1206.15 ± 14.7 µg mL(-1)) and cysteine (20.63 ± 0.4 µg mL(-1)) in the cultivation fluid. The strain also showed the highest level of keratinase activity (39.10 ± 0.4 U mL(-1)). These data indicates that the Bacillus cereus KB043 could be useful in management of poultry wastes.