Kurchenko Vladimir, Halavach Tatsiana, Yantsevich Alexey, Shramko Mariya, Alieva Lyudmila, Evdokimov Ivan, Lodygin Alexey, Tikhonov Vladimir, Nagdalian Andrey, Ali Zainy Faten M, Al-Farga Ammar, ALFaris Nora Abdullah, Shariati Mohammad Ali
Department of Biology, Belarusian State University, Minsk, Belarus.
Laboratory of Food and Industrial Biotechnology, Faculty of Food Engineering and Biotechnology, North Caucasus Federal University, Stavropol, Russia.
Front Nutr. 2024 Sep 16;11:1441355. doi: 10.3389/fnut.2024.1441355. eCollection 2024.
The influence of chitosan's physicochemical characteristics on the functionality of lactic acid bacteria and the production of lactic acid remains very obscure and contradictory to date. While some studies have shown a stimulatory effect of oligochitosans on the growth of Lactobacillus spp, other studies declare a bactericidal effect of chitosan. The lack and contradiction of knowledge prompted us to study the effect of chitosan on the growth and productivity of in the presence of chitosan and its derivatives.
We used high molecular weight chitosan (350 kDa) and oligochitosans (25.4 and 45.3 kDa). The experiment was carried out with commercial strain of and the low fat skim cow milk powder reconstituted with sterile distilled water. After fermentation, dynamic viscosity, titratable acidity, pH, content of lactic acid, colony forming units, chitosan and oligochitosans radii were measured in the samples. Fermented dairy products were also examined using sodium dodecyl sulfate electrophoretic analysis, gas chromatography-mass spectrometry and light microscopy.
The results of the study showed that when was cultured in the presence of 25.4 kDa oligochitosans at concentrations of 0.0025%, 0.005%, 0.0075% and 0.01%, the average rate of LA synthesis over 24 hours was 11.0 × 10 mol/L/h, 8.7 × 10 mol/L/h, 6.8 × 10 mol/L/h, 5.8 × 10 mol/L/h, respectively. The 45.3 kDa oligochitosans had a similar effect, while the average rate of lactic acid synthesis in the control sample was only 3.5 × 10 mol/L/h. Notably, 350 kDa chitosan did not affect the rate of lactic acid synthesis compared with the control sample. Interestingly, interaction of chitosan with led to a slowdown in the synthesis of propanol, an increase in the content of unsaturated and saturated fatty acids, and a change in the composition and content of other secondary metabolites. The quantity of in a sample with 0.01% chitosan exceeded their content in the control sample by more than 1,700 times. At the same chitosan concentration, the fermentation process was slowed down, increasing the shelf life of the fermented milk product from 5 to 17 days while maintaining a high content of (6.34 × 10 CFU/g).
壳聚糖的物理化学特性对乳酸菌功能及乳酸产生的影响至今仍非常模糊且相互矛盾。虽然一些研究表明低聚壳聚糖对乳酸杆菌属的生长有刺激作用，但其他研究则宣称壳聚糖具有杀菌作用。知识的匮乏和矛盾促使我们研究壳聚糖及其衍生物存在时对[具体菌种]生长和生产力的影响。
我们使用了高分子量壳聚糖（350 kDa）和低聚壳聚糖（25.4 kDa和45.3 kDa）。实验采用[具体商业菌株]以及用无菌蒸馏水重构的低脂脱脂奶粉进行。发酵后，测量样品中的动态粘度、可滴定酸度、pH值、乳酸含量、菌落形成单位、壳聚糖和低聚壳聚糖半径。还使用十二烷基硫酸钠电泳分析、气相色谱 - 质谱联用和光学显微镜对发酵乳制品进行了检测。
研究结果表明，当[具体菌种]在浓度为0.0025%、0.005%、0.0075%和0.01%的25.4 kDa低聚壳聚糖存在下培养时，24小时内乳酸合成的平均速率分别为11.0×10⁻³mol/L/h、8.7×10⁻³mol/L/h、6.8×10⁻³mol/L/h、5.8×10⁻³mol/L/h。45.3 kDa低聚壳聚糖有类似效果，而对照样品中乳酸合成的平均速率仅为3.5×10⁻³mol/L/h。值得注意的是，与对照样品相比，350 kDa壳聚糖不影响乳酸合成速率。有趣的是，壳聚糖与[具体菌种]的相互作用导致丙醇合成减缓、不饱和脂肪酸和饱和脂肪酸含量增加以及其他次生代谢产物的组成和含量发生变化。含0.01%壳聚糖的样品中[具体菌种]的数量比对照样品中的含量高出1700多倍。在相同壳聚糖浓度下，发酵过程减缓，发酵乳制品的保质期从5天延长至17天，同时保持较高的[具体菌种]含量（6.34×10⁸CFU/g）。
