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Applications of Marine Biochemical Pathways to Develop Bioactive and Functional Products
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Toni-Ann Benjamin, Imran Ahmad, Muhammad Bilal Sadiq
For chitin recovery from seafood-processing wastes, different fermentation strategies are used. Fermentation using lactic acid bacteria, Bacillus sp., and Pseudomanas species are commonly used to produce chitin from shrimp waste. In 2013, Ghorbel-Bellaaj et al. extracted chitin via microbial fermentation using Bacillus pumilus A1 and found it effective in producing a high-quality strain. Another extraction method is liquid fermentation. Doan et al. (2019) used an alkaline protease-producing strain (Brevibacillus parabrevis) and found that this method produced high deproteinization rates, and the supernatant had high growth-enhancing activity on lactic acid bacteria. This method would be difficult to apply at the industrial scale due to the risk of microbial contamination (Ozogul et al., 2021). Enzyme-assisted extraction is also a nonthermal processing technique and can be applied to chitosan via extraction from chitin via a chitin deacetylase enzyme. However, pretreatment is needed, such as grinding, sonication, and heating (Yadav et al., 2019).
Fabrication of Bionanocomposites from Chitosan
Published in Jissy Jacob, Sravanthi Loganathan, Sabu Thomas, Chitin- and Chitosan-Based Biocomposites for Food Packaging Applications, 2020
Anuradha Biswal, Sarat K. Swain
The biological/enzymatic deacetylation of chitin to chitosan is carried out in the presence of the enzyme chitin deacetylase. Chitin deacetylase belongs to the carbohydrate esterase family that is used in hydrolysis of the acetamido group of the N-acetylglucosamine units of chitin to produce acetic acid and glucosamine units. The deacetylase can also be extracted from organisms such as bacteria (V. cholera), insects (Helicoverpa armigera, Helicoverpa armigera, Drosophila melanogaster), and fungi (C. Lindemuthianum, F. Velutipes, M. Racemosus, A. Niger). In order to increase the efficiency of enzymatic deacetylation, such physical treatments as grinding, sonication, derivatization, and heating occur before deacetylation (Zhao, Park, and Muzzarelli 2010).
Pharmaceutical Application of Chitosan Derivatives
Published in Amit Kumar Nayak, Md Saquib Hasnain, Dilipkumar Pal, Natural Polymers for Pharmaceutical Applications, 2019
Fiona Concy Rodrigues, Krizma Singh, Goutam Thakur
This is an alternative method to produce CS from crustacean shells. Unlike chemical methods, demineralization of crustacean shells is carried out by the lactic acid-producing bacteria. The reaction works in a way that when the lactic acid reacts with calcium carbonate, it leads to the formation of calcium lactate. The calcium lactate is precipitated and removed (Imen and Fatih, 2016). Further, certain enzymes proteases which are extracted from bacteria are used for deproteination of crustacean shells. This is achieved by fermenting the crustacean with different bacterial species such as Pseudomonas aeruginosa K-187, Serratia marcescens FS-3, and Bacillus subtilis (Jo et al., 2008). Deacetylation of chitin is carried out by chitin deacetylase (Cai et al., 2006). The enzyme, chitin deacetylase, was first found in Mucor rouxii and later was produced from bacteria such as Serratia sp. and Bacillus sp. which were used to generate CS (Imen and Fatih, 2016).
Enhancement of the mechanical properties of chitosan
Published in Journal of Biomaterials Science, Polymer Edition, 2020
Chitosan (CS) is procured from chitin, the second most widespread natural polysaccharide, after a deacetylation process (Figure 1). This Deacetylation process is accomplished either through employing concentrated sodium hydroxide or enzymatically via the action of chitin deacetylase. Accordingly, the structure of CS comprises a mixture of N-acetylglucosamine and glucosamine which are appended together into linear chains through β-(1-4) connections [1]. CS offers many advantages which caused it to be involved in different applications. For instance, CS is biocompatible, biodegradable, exhibits anti-microbial activity, and also promotes wound healing. Moreover, its structure is similar to that of the glycosaminoglycan’s which is an integral constituent of the natural extracellular matrix. Hence, it was considered in tissue engineering applications [2]. It was also investigated as a vehicle for injectable drug delivery systems [3, 4] and for embolization of blood vessels [5]. Another advantageous trait of CS is its outstanding film forming capacity which, together with the aforementioned advantages, led to the investigation of CS as an edible packaging material for foods that would enhance the foods’ quality and extend their shelf-life [6, 7]. Furthermore, the CS’s amino and hydroxyl groups imparted adsorptive abilities to CS films; hence these films could be employed to get rid of pollutants [8]. The CS amino groups also enabled its utilization as a covalent immobilization matrix. A dialdehyde compound, glutaraldehyde (GA) was first allowed to react with the CS’s nucleophilic amino groups. This led to the binding of the reactive GA moieties to the CS beads. These GA moieties also offered reactive aldehyde groups during the beads reaction with enzymes which eventually resulted in the covalent immobilization of these enzymes [9].
Banana peels as a cost effective substrate for fungal chitosan synthesis: optimisation and characterisation
Published in Environmental Technology, 2023
Kumaresan Priyanka, Mridul Umesh, Kathirvel Preethi
Anova for BBD (Supplementary File Table 1) indicates that the obtained model was highly significant from F value (673.19) evaluation and states that only 0.01% chance due to noise. The R2 value of 0.9988 (very close to 1) indicates that 99.88% of total variation was identified by the model in chitosan yield and reveals the strong influence of three major factors among other parameters and also signifies that a very high correlation exists between actual and predicted values when R2 value lies within the range of 0–1.0 [25]. Hence the present study typifies a reliable correlation as the predicted R2 (0.9880) was in accordance with adjusted R2 (0.9974) which is further exemplified by constructing 3D surface plots. The effects of interacting variables were inferred from the configuration of the counter plots. Elliptical nature implies better interaction whereas circular plot reflects a negligible interaction [26]. Figure 1(a) describes a positive interaction between pH and incubation period and inferred that maximum chitosan yield occurs at 6 and 168 hrs respectively which illustrate that an increase in pH up to midpoint promoted chitosan production after which the yield was gradually reduced. In contrast, further increase in incubation period resulted in steady increase of biopolymer. Longer incubation period has an influential effect in both biomass and chitosan as more amount of chitosan free chitosan is accumulated at late exponential phase which may differ based on microbial culture and their physicochemical parameters provided for their cultivation. A moderate interactive effect of ammonium nitrate and incubation time is shown in Figure 1(b) which is evidenced from the elliptical plot where the pH is maintained at zero coded level. Chitosan being a nitrogenous compound exhibits a profound influence on maintaining the integrity of the fungal cell wall. Previous investigations delineate the capability of ingesting ammonium ions directly as a nitrogen supplement by fungal cell which in consequence potentiates a two fold increase in fungal biomass production. Habibi et al [27] have investigated the effect of different concentration of ammonium ions on chitosan yield using apple waste extract and reported that there was notable increase from 68.81 mg/g of biomass to 163.02 mg/g of biomass which signifies ammonium nitrate as a prompt requirement to enhance the chitosan yield which corroborates with the present study. Figure 1(c) demonstrates a strong interaction between pH and ammonium nitrate. Both these factors amplified the production when increased from lower level and maximum chitosan was achieved at their intermediate values beyond which the productivity was decreased. This may be attributed to the decreased activity of chitin deacetylase enzyme which favours the conversion of chitin to chitosan in the fungal cell wall mostly at the acidic pH [28].