Screening of novel yeast inulinases and further application to bioprocesses.

In this study, several microbial strains were isolated and their ability to inulinase biosynthesis was evaluated. The novel yeast strain Talf1, identified as Zygosaccharomyces bailii, was the best inulinase producer, attaining 8.67 U/ml of inulinase activity when JA juice was used as the inducer substrate. Z. bailii strain Talf1 and/or its enzymatic crude extract were further applied for bioethanol production and biodesulfurization (BDS) processes, using inulin and JA juice as carbon source. In a consolidated bioprocessing for ethanol production from 200g/l inulin, Z. bailii strain Talf1 was able to produce 67g/l of ethanol. This ethanol yield was improved in a simultaneous saccharification and fermentation (SSF) process, with the ethanologenic yeast Saccharomyces cerevisiae CCMI 885 and the Talf 1 inulinases, achieving a production of 78g/l ethanol. However, the highest ethanol yield (∼48%) was obtained in a SSF process from JA juice (∼130g/l fermentable sugars), where the S. cerevisiae produced 63g/l ethanol. Relatively to the dibenzothiophene BDS tests, the G. alkanivorans strain 1B achieved a desulfurization rate of 4.8μM/h within a SSF process using Talf1 inulinases and JA juice, highlighting the potential of JA as a less expensive alternative carbon source. These results showed the high potential of Z. bailii strain Talf1 inulinases as a versatile tool for bioprocesses using inulin-rich materials. PMID: 23419675 [PubMed - as supplied by publisher]
Source: New Biotechnology - Category: Biotechnology Authors: Tags: N Biotechnol Source Type: research