Optimization of chitin yield from shrimp shell waste by Bacillus subtilis and impact of gamma irradiation on production of low molecular weight chitosan

Biotechnological recovery of chitin from crustacean waste

“…Some species of bacteria have been studied, as Bacillus spp. which have a high proteolytic capacity (Liu et al 2020;Doan et al 2019;Dun et al 2018;Mhamdi et al 2017;Gamal et al 2016;Younes et al 2016;Pachapur et al2015;Sedaghat et al 2015;Hajji et al 2015;Younes et al 2014;Liu et al 2014;Ghorbel-Bellaaj et al 2013;Junianto et al 2013;Mao et al 2013;Younes et al 2012;Wahyuntari et al 2011;Manni et al 2010;Hoffmann et al 2010;Sorokulova et al 2009). Similarly, another genus highly used is Lactobacillus, not only due to its high proteolytic activity, but also to its capacity to produce lactic acid, which has allowed to perform DP and DM in a single step.…”

“…Although those methods have been commercially viable, they represent an environmental cost that needs to be addressed. As an alternative, research efforts have been made to contribute to replace chemical procedures by biotechnological ones which are environmentally friendly as shown in Figure 1 Liu et al 2014;Francisco et al 2015;Bashandy et al 2016;Sedaghat et al 2017;Zhang et al 2017;Hamdi et al 2017;Castro et al 2018;Dun et al 2018;Liu et al 2020). Comparatively high cost of their manufacturing process, has been reported as a disadvantage for the use of chitin in some industries (Sini et al 2007), however, a biological method to recover this biopolymer seems to be low cost and feasible to scale it up to industrial level (Dun et al 2018).…”

Reclamation of Fishery Processing Waste: A Mini-Review

“…Chemical treatments can produce purer chitin and chitosan than biological procedures; however, the waste materials from acid and alkali treatments contribute to environmental pollution and reduce the chitin quality. As such, chitin-containing waste could potentially become a precious bioresource if converted by biological processes to create high-value-added products [2,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90] (Table 2).…”

“…The bioconversion procedure is a simple, inexpensive alternative to chemical methods employed in the preparation of chitin. To overcome the drawbacks of chemical procedures, studies have isolated many proteolytic and/or chitinolytic enzyme-producing bacteria using shrimp and crab shells as their sole carbon/nitrogen (C/N) source [2,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91]. It is assumed that the shrimp and crab shells will be deproteinized by the protease produced by the bacteria during fermentation.…”

Chitosan Applications on Pharmaceutical Sciences: A Review

“…There are different alternatives to carry out these steps, including chemical and enzymatic procedures. Since the former involves the use of strong alkali and acids, they present some disadvantages, such as the polymer hydrolysis, the lack of reproducibility of the final physiological properties, and environmental pollution, making it necessary to further neutralize and detoxify the wastewater [23]. The replacement of one or several stages by biotechnological methods, including the use of enzymes, avoids some of these drawbacks, however, there are also some disadvantages associated with this technology, such as high residual protein, longer reaction times and high costs of enzymes, limiting the enzymatic methods for industrial applications [24].…”