Optimization of spray-drying conditions for obtaining Bacillus sp. SMIA-2 protease powder

Abstract

Microbial proteases, especially from Bacillus spp., have enormously been exploited for a broad variety of applications such as for physiological processes, food and feedstuff, detergents, as well as in the pharmaceutical and leather. In this work, proteases produced by the thermophilic Bacillus sp. SMIA-2 submerged cultures were spray-dried in an attempt to improve its stability for applications in industry. The enzymatic extract was dried using drying adjuvants, and optimal conditions for preserving enzymatic activity were studied following a statistical experimental design. The spray process factors studied were the drier air inlet temperature and the adjuvants concentrations. The responses analyzed were the enzymatic activity and mass recovered of the powder after spray drying. Additionally, the stability of the powder was assessed during 180 days at room temperature. The results revealed that satisfactory levels of enzymatic activity were obtained when 0.5% (w/v) carboxymethylcellulose and 1.0% (w/v) maltodextrin were incorporated to enzymes solutions and the spray drier inlet temperature was 110 ºC. Furthermore, this dried protease extracts showed potential for future commercial applications because of their stability at room temperature for 180 days.

Stable and effective eco-enzyme cocktails in powder and liquid form of Stachybotrys microspora used as detergent additives

“…Moreover, the addition of NaCl at 0.1% (v/v) in the medium containing 15 g/L of wheat bran significantly improved proteases, amylases, and endoglucanases co-production by 1.22 folds, 1.23 folds, and 1.6 folds, respectively ( Table 2 ). Previous studies [ [42] , [43] , [44] ] have reported that NaCl enhances enzyme secretion. Indeed, this salt exhibits a crucial role in protecting and stabilizing proteins from inactivation [ 42 , 43 ].…”

“…Between the excipients evaluated, maltodextrin gave the best effects. Similarly, Naganthran et al showed the important role of maltodextrin in the stability of protease, amylase, and lipase [ 44 ].

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“…The advantage of freeze-drying is that simultaneous freezing and drying generates a dry, active, and stable enzyme. Additionally, several studies have shown that the inclusion of additives such as polyols (an organic compound containing multiple alcoholic hydroxyl groups) and polysaccharides improves the stability of the protein during freeze-drying and storage in solid detergents [ 13 , 44 , 45 ].…”