Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 2/22 Stefanowskiego Str., Lodz, 90-537, Poland.
Microb Cell Fact. 2024 Sep 28;23(1):258. doi: 10.1186/s12934-024-02529-4.
Chitosan oligosaccharides (COS) have great potential for applications in several fields, including agriculture, food industry or medicine. Nevertheless, the large-scale use of COS requires the development of cost-effective technologies for their production. The main objective of our investigation was to develop an effective method of enzymatic degradation of chitosan in a column reactor using Mucor circinelloides IBT-83 cells, immobilized in a polyurethane foam (PUF). These cells serve as a source of chitosanolytic enzymes.
The study revealed that the process of freeze-drying of immobilized mycelium increases the stability of the associated enzymes during chitosan hydrolysis. The use of stabilized preparations as an active reactor bed enables the production of COS at a constant level for 16 reactor cycles (384 h in total), i.e. 216 h longer compared to non-stabilized mycelium. In the hydrolysate, oligomers ranging in structure from dimer to hexamer as well as D-glucosamine were detected. The potential application of the obtained product in agriculture has been verified. The results of phytotests have demonstrated that the introduction of COS into the soil at a concentration of 0.01 or 0.05% w/w resulted in an increase in the growth of Lepidium sativum stem and root, respectively (extensions by 38 and 44% compared to the control sample).
The research has verified that the PUF-immobilized M. circinelloides IBT-83 mycelium, which has been stabilized through freeze-drying, is a promising biocatalyst for the environmentally friendly and efficient generation of COS. This biocatalyst has the potential to be used in fertilizers.
壳寡糖（COS）在农业、食品工业和医药等多个领域具有巨大的应用潜力。然而，要大规模应用 COS，就需要开发具有成本效益的生产技术。我们研究的主要目的是开发一种在柱式反应器中使用固定化在聚氨酯泡沫（PUF）中的毛霉（Mucor circinelloides）IBT-83 细胞有效降解壳聚糖的方法，这些细胞是壳聚糖酶的来源。
研究表明，固定化菌丝体的冻干过程增加了壳聚糖水解过程中相关酶的稳定性。使用稳定化制剂作为活性反应器床，可以在 16 个反应器循环（共 384 小时）中保持 COS 的恒定产量，即比非稳定化菌丝体延长了 216 小时。在水解产物中，检测到结构从二聚体到六聚体的低聚物以及 D-葡萄糖胺。已经验证了所获得的产物在农业中的潜在应用。植物测试的结果表明，将 COS 以 0.01 或 0.05%w/w 的浓度引入土壤中，分别导致蕹菜茎和根的生长增加（与对照样品相比分别增加了 38%和 44%）。
研究证实，通过冻干稳定化的 PUF 固定化毛霉（Mucor circinelloides）IBT-83 菌丝体是一种很有前途的生物催化剂，可用于环保、高效地生成 COS。这种生物催化剂有可能用于肥料。
