Isolation and identification of bacterial strain I33M producing milk-clotting enzyme: Optimization of culture parameters using response surface

A strain I33M which produces a milk-clotting enzyme was screened from Algerian soil near a dairy factory. This strain was identified as Bacillus mojavensis based on morphology and internal transcription spacer sequence. Sequencing analysis of 16S rDNA gene showed 100% identity of the tested strain with the B. mojavensis in the database. Phylogenetic analysis of this strain showed that it was most closely related to Bacillus subtilis strain. The optimum levels of these significant parameters to obtain the highest milk clotting activity and the lowest proteolytic activity were determined employing the response surface methodology (RSM), which revealed these as follows: wheat bran 7%, casein 0.094%, temperature 39°C, agitation size (rpm) 150. Among the various variables screened, agitation and temperature were most significant in submerged fermentation (SmF). The optimal value of milk clotting activity (MCA) is esteemed at 2.40. Key words: Milk clotting protease, Bacillus, response surface methodology, sequencing analysis

Deuxièmes journées nationales de biologie 15-16 novembre 2005 : les biotechnologies, biologie moléculaire et cellulaire, biologie des organismes et dse populations

68 p. : ill. ; 30 c

Production of rennet like enzymes by solid state fermentation using local isolates of Aspergillus niger and Rhizopus stolonifer

info:eu-repo/semantics/publishe

Extracellular protease from mucor pusillus : purfication and characterization

Extracellular protease from Mucor pusillus was purified 18-fold with 7.56% recovery by ion-exchange chromatography and gel filtration. The enzyme was found to be monomeric in nature, having a molecular mass of 49 kDa. The enzyme acted optimally at 50°C and was stable in the temperature range 30–50°C. It was completely inactivated by heating for 30 min at 65°C. The optimum of activity for the purified extract was observed at milk CaCl2 concentration of 0.02 m and at milk pH of 5. These properties, except for temperature, were similar to those of renne

Essential oil of cytisus triflorus L'Her

The essential oil of Cytisus triflorus L'Her., a Mediterranean species was obtained by steam distillation and identified by GC and GC-MS. 61 compounds were determined. The oxygenated terpenoidic components constituted the most important fraction (64%) followed by the fatty acids (8.2%) and the hydrocarbonated fractions (10.7%