title: Production and optimization of thermophilic alkaline protease in solid-state fermentation by Streptomyces sp. CN902.
abstract: The purpose of the present research is to study the production of thermophilic alkaline protease by a local isolate, Streptomyces sp. CN902, under solid state fermentation (SSF). Optimum SSF parameters for enzyme production have been determined. Various locally available agro-industrial residues have been screened individually or as mixtures for alkaline protease production in SSF. The combination of wheat bran (WB) with chopped date stones (CDS) (5:5) proved to be an efficient mixture for protease production as it gave the highest enzyme activity (90.50 U g(-1)) when compared to individual WB (74.50 U g(-1)) or CDS (69.50 U g(-1)) substrates. This mixed solid substrate was used for the production of protease from Streptomyces sp. CN902 under SSF. Maximal protease production (220.50 U g(-1)) was obtained with an initial moisture content of 60%, an inoculum level of 1 x 10(8) (spore g(-1) substrate) when incubated at 45 degrees C for 5 days. Supplementation of WB and CDS mixtures with yeast extract as a nitrogen source further increased protease production to 245.50 U g(-1) under SSF. Our data demonstrated the usefulness of solid-state fermentation in the production of alkaline protease using WB and CDS mixtures as substrate. Moreover, this approach offered significant benefits due to abundant agro-industrial substrate availability and cheaper cost.
authors.affiliation: Unité de Microbiologie et Biologie Moléculaire, Centre Nationale des Sciences et Technologie Nucléaires, Technopole de Sidi Thabet 2020, Tunis, Tunisia. hadeer.lazim@cnstn.rnrt.tn
authors.forename: Hadeer
authors.initials: H
authors.lastname: Lazim
authors.forename: Houda
authors.initials: H
authors.lastname: Mankai
authors.forename: Nedra
authors.initials: N
authors.lastname: Slama
authors.forename: Insaf
authors.initials: I
authors.lastname: Barkallah
authors.forename: Ferid
authors.initials: F
authors.lastname: Limam
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D003470:Culture Media / Q000378:metabolism; D046508:Culture Techniques / Q000379:methods*; D010450:Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D005285:Fermentation; D007218:Industrial Microbiology; D013302:Streptomyces / Q000737:chemistry / Q000201:enzymology*; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D010450:Endopeptidases; C087822:alkaline protease