Isolation, Biochemical Characterisation and Identification of Thermotolerant and Cellulolytic Paenibacillus lactis and Bacillus licheniformis.

RESEARCH BACKGROUND: Cellulose is an ingredient of waste materials that can be converted to other valuable substances. This is possible provided that the polymer molecule is degraded to smaller particles and used as a carbon source by microorganisms. Because of the frequently applied methods of pretreatment of lignocellulosic materials, the cellulases derived from thermophilic microorganisms are particularly desirable. EXPERIMENTAL APPROACH: We were looking for cellulolytic microorganisms able to grow at 50 °C and we described their morphological features and biochemical characteristics based on carboxymethyl cellulase (CMCase) activity and the API® ZYM system. The growth curves during incubation at 50 °C were examined using the BioLector® microbioreactor. RESULTS AND CONCLUSIONS: Forty bacterial strains were isolated from fermenting hay, geothermal karst spring, hot spring and geothermal pond at 50 °C. The vast majority of the bacteria were Gram-positive and rod-shaped with the maximum growth temperature of at least 50 °C. We also demonstrated a large diversity of biochemical characteristics among the microorganisms. The CMCase activity was confirmed in 27 strains. Hydrolysis capacities were significant in bacterial strains: BBLN1, BSO6, BSO10, BSO13 and BSO14, and reached 2.74, 1.62, 1.30, 1.38 and 8.02 respectively. Rapid and stable growth was observed, among others, for BBLN1, BSO10, BSO13 and BSO14. The strains fulfilled the selection conditions and were identified based on the 16S rDNA sequences. BBLN1, BSO10, BSO13 were classified as Bacillus licheniformis, whereas BSO14 as Paenibacillus lactis. NOVELTY AND SCIENTIFIC CONTRIBUTION: We described cellulolytic activity and biochemical characteristics of many bacteria isolated from hot environments. We are also the first to report the cellulolytic activity of thermotolerant P. lactis. Described strains can be a source of new thermostable cellulases, which are extremely desirable in various branches of circular bioeconomy.

Preparative scale application of Mucor circinelloides ene-reductase and alcohol dehydrogenase activity for the asymmetric bioreduction of α,ß-unsaturated γ-ketophosphonates.

The fungus Mucor circinelloides exhibits high potential for green chemistry and technological applications. Recently M. circinelloides, which so far was considered mainly as a platform for biodiesel production, was found to exhibit high ene-reductase activity. In our current research we applied this promising microorganism to the biotransformation of a series of α,ß-unsaturated γ-ketophosphonates. The biotransformations were conducted using cheap corn steep liquor or minimal media. The products were obtained with excellent enantiomeric purity (>99% ee in most cases) and in good isolated yields, highlighting the great potential of this microorganism for asymmetric synthesis. Moreover, the products obtained may be further applied as chiral building blocks for the synthesis of biologically active compounds, such as glutamic acid or fosmidomycin derivatives.