Silajdan Elde Edilen Lactobacillus sp. ve Lb. rhamnosus,’ un bazı Enzim Aktivitelerinin İncelenmesi

Abstract

Probiotic lactic acid bacteria are vital microbial group for fermentation of silage, which is crucial importance particularly for dairy animal nutrition. These microorganisms are able to degrade amino acids, carbohydrates and fatty acids, our knowledge, however, about their other enzymatic activities is still limited. To investigate the inulinase and invertase activities of silage originated Lactobacillus sp and Lactobacillus rhamnosus, the isolates were incubated for 24h, 36h and 48h in LB broth and MRS broth. Supernatant and cell associated enzyme activities were determined at pH: 6.0 using inulin and sucrose as substrates, and their specific and total enzyme activities were analysed comparatively. Lactobacillus sp showed the highest invertase activity as 22.1 mg/ml (cell associated) for 24h incubation, whilst the utmost invertase activity was observed as 20 mg/ml at the end of 36h incubation period for supernatants. Same enzyme activities were determined as 20,1 mg/ml and 19,9 mg/ml for 24h incubation, for cell associated and supernatant samples of Lb rhamnosus respectively. The highest cell associated inulinase activity of Lactobacillus sp was recorded as 20,1 mg/ml for 36h incubation time while the maximal activity for supernatant was recorded at 24h incubation. Maximum cell associated and supernatant activities of the isolate was observed as 24,6 mg/ml and 26, mg/ml respectively. Both isolates showed noteworthy amount of invertase and inulinase activities which makes them potential silage inoculants.