Analysis of exopolysaccharide production patterns of Cordyceps militaris under various light-emitting diodes

Photoregulation of the biosynthetic activity of the edible medicinal mushroom Lentinula edodes in vitro

The findings of the study demonstrate the impact of low-intensity laser and quasi-monochromatic light on the biosynthetic activity of the edible medicinal fungus L. edodes during submerged cultivation. An artificial lighting installation based on matrices of light-emitting diodes (LED) emitting light at 470 nm (blue), 530 nm (green), 650 nm (red), and argon gas laser (488 nm) was used. Irradiation with blue and red LED and laser led to a shortening of the lag phase by 2 days and an increase in the mycelial mass. Irradiation with laser light resulted in the highest mycelial mass yield (14.1 g/L) on the 8th day of cultivation. Irradiation in all used wavelength ranges caused an increase in the synthesis of both extracellular and intracellular polysaccharides. Laser light at 488 nm and LED at 470 nm proved to be the most effective. Irradiation with red, green, and blue laser light caused an increase in the total amount of fatty acids in the mycelial mass compared to the control. A significant distinction in qualitative composition was observed: short-chain acids C6‒C12 compounds were produced under red light irradiation, whereas long-chain C20‒C24 were formed under green light irradiation. The most significant changes in the aromatic profile of the mycelial mass and culture liquid were recorded upon irradiation with green light. The content of aromatic components increased 24.6 times in the mycelial mass and 38.5 times in the culture liquid. The results suggest the possibility of using low-intensity quasi-monochromatic light for targeted regulation of L. edodes biosynthetic activity.

A review on polysaccharide biosynthesis in Cordyceps militaris

Cordyceps militaris (C. militaris) is an edible parasitic fungus with medicinal properties. Its bioactive polysaccharides are structurally diverse and exhibit various metabolic and biological activities, including antitumor, hypoglycemic, antioxidant, hypolipidemic, anti-inflammatory, immunostimulatory, and anti-atherosclerotic effects. These properties make C. militaris-derived polysaccharides a promising candidate for future development. Recent advancements in microbial fermentation technology have enabled successful laboratory cultivation and extraction of these polysaccharides. These polysaccharides are structurally diverse and exhibit various biological activities, such as immunostimulatory, antioxidant, antitumor, hypolipidemic, and anti-atherosclerotic effects. This review aims to summarize the structure and production mechanisms of polysaccharides from C. militaris, covering extraction methods, key genes and pathways involved in biosynthesis, and fermentation factors that influence yield and activity. Furthermore, the future potential and challenges of utilizing polysaccharides in the development of health foods and pharmaceuticals are addressed. This review serves as a valuable reference in the fields of food and medicine, and provides a theoretical foundation for the study of polysaccharides.

Light Irradiation Coupled with Exogenous Metal Ions to Enhance Exopolysaccharide Synthesis from Agaricus sinodeliciosus ZJU-TP-08 in Liquid Fermentation

To promote Agaricus sinodeliciosus var. Chaidam ZJU-TP-08 growth and metabolites accumulation, a novel integrated strategy was developed by adopting high levels of metal ions coupled with light treatment. The results revealed that yellow and blue light could significantly promote biomass and exopolysaccharides production, respectively. Furthermore, the yellow–blue light shift strategy could stimulate exopolysaccharides formation. Ca²⁺ ions coupled with blue light mostly promoted exopolysaccharides production related to oxidative stress, which was 42.00% and 58.26% higher than that of Ca²⁺ ions coupled with the non-light and dark cultivation without Ca²⁺ ions in 5-L bioreactor. RNA-seq was performed to uncover the underlined molecular mechanism regulated by light-induced gene expressions in exopolysaccharides biosynthesis and oxidative stress. The findings of this work provide valuable insights into adopting metal ions coupled with the light-assisted method for the macrofungus submerged fermentation for exopolysaccharides production.

Structure and hypoglycemic activity of a novel exopolysaccharide of Cordyceps militaris

A novel neutral exopolysaccharide (EPS-III) was isolated from culture broth of Cordyceps militaris (C. militaris). The EPS-III was a homogeneous polysaccharide with M_w of 1.56 × 10³ kDa. The yield of EPS-III from culture broth was 123.2 ± 3.1 mg/L and the sugar content was 93.32 ± 0.87%. The backbone of EPS-III was mainly consisted of →4)-α-D-Galp-(1→, while →3, 6)-α-D-Manp-(1→, →4)-α-D-Manp-(1→, →3)-β-D-Galp-(1→ and →3)-α-D-Glcp-(1→ were distributed in the backbone or in the branch chains. The EPS-III had helix structure when dissolved in weak alkaline solution. It also had branched and intertwined form on the surface. The inhibition of α-glucosidase significantly increased as the increase of purity of exopolysaccharides. The EPS-III had effective inhibition on the α-glucosidase with dose-effect relationship. Besides, the results of hypoglycemic activity analysis in vivo indicated that EPS-III can alleviate weight loss, reduce plasma glucose concentration, improve glucose tolerance, protect immune organs and repair dyslipidemia to relieve diabetes in STZ-induced diabetic mice. The manuscript first studied the hypoglycemic activity of exopolysaccharide of by C. militaris, proving and promoting the application value of culture broth. The structure characterization of EPS-III laid experimental foundations on the exploration of structure-activity relationship.

Extracellular polysaccharide biosynthesis in Cordyceps

Cordyceps is a parasitic edible fungus with a variety of metabolically active ingredients. The main active ingredient, extracellular polysaccharide (EPS), shows favourable application prospects in prevention and treatment of certain diseases. EPS extracted from different parts of various Cordyceps species can be used in health foods or medicinal preparations because of the structural diversity and multiple bioactivities. In terms of the complexity of composition and structure, researchers have speculated on the anabolic pathways of EPSs and the genes involved in the synthesis process. Studies to increase the yield of polysaccharides are limited because the synthesis pathways and anabolic regulation mechanisms of Cordyceps exopolysaccharide remain unknown. This review summarises the current researches in the yield of Cordyceps polysaccharides. A mechanism for the biosynthesis of Cordyceps polysaccharides was proposed by referring to the polysaccharide synthesis in other species. Furthermore, we also discuss the future perspective and ongoing challenges of EPS in uses of health foods and pharmaceutics.

Application of microbial extracellular carbohydrate polymeric substances in food and allied industries

Extracellular polymeric substances (EPS) are biopolymers, composed of polysaccharides, nucleic acids, proteins and lipids, which possess unique functional properties. Despite significant strides made in chemical production processes for polymers, the niche occupied by exopolysaccharides produced by bacteria, yeast or algae is steadily growing in its importance. With the availability of modern tools, a lot of information has been generated on the physico-chemical and biological properties using spectrometric tools, while advanced microscopic techniques have provided valuable insights into the structural-functional aspects. The size of EPS generally ranges between 10 and 10,000 kDa. The wide spectra of applications of EPS as adhesives, stabilizer, gelling, suspending, thickening agent, and surfactants in food and pharmaceutical industries are observed. The health benefits of these EPS enable the improvement of dual function, added value, and green products. This review summarizes previous work on the structural composition, rheological and thermal behaviour, and biosynthetic pathways of EPS and bioprocesses developed for their production. This review also considers each of the above factors and presents the current knowledge on the importance and refinement of available downstream protocols and genetic engineering towards specific food applications, which can help to diversify their prospects in different food and allied industries.

Optimal economic productivity of exopolysaccharides from lactic acid bacteria with production possibility curves

It is important that exopolysaccharides (EPS) of lactic acid bacteria (LAB) with antioxidant activities are produced economically, as it can confer beneficial effects on human health. A model of production possibility curve (PPC) was conducted to the optimal productivity of EPS for the purpose of economic production. The results revealed that the optimal productivity of EPS was approached to the set by NB (90%) and MRS (55%) broth from PPC with equation of PPC(Y) = 100-0.0335*EXP(0.08*X). The EPS productivity and yield of strain LaP with optimal production set (OPS) were, respectively, 291.0 ± 2.6 mg and 13.5 ± 0.7%, and the cost of OPS can be saved by about 31.6%, while that for strain BaP were 280.7 ± 2.5 mg and 13.0 ± 0.7%, respectively, and with 31.6% saved as well. Besides, the EPS produced from PPC mode has appropriate antioxidant ability with 34.6 ± 0.7% (LaP) and 37.6 ± 0.9 (%) (BaP) of DPPH radical scavenging activity under the economic cost. The strategy of controlling the medium composition not only could improve the productivity of EPS, but also enhance the antioxidant effects of EPS. Both LaP and BaP with antioxidant potential may be useful as supplements in the health-promoting food industry.

Screening of a beta-cypermethrin-degrading bacterial strain Brevibacillus parabrevis BCP-09 and its biochemical degradation pathway

A novel beta-cypermethrin (Beta-CP)-degrading strain isolated from activated sludge was identified as Brevibacillus parabrevis BCP-09 based on its morphological and physio-biochemical characteristics, and 16S rRNA gene analysis. Strain BCP-09 could effectively degrade Beta-CP at pH 5.0-9.0, 20-40 °C, and 10-500 mg L^-1 Beta-CP. Under optimal conditions (pH 7.41, 38.9 °C, 30.9 mg L^-1 Beta-CP), 75.87% Beta-CP was degraded within 3 days. Beta-CP degradation (half-life, 33.45 h) and strain BCP-09 growth were respectively described using first-order-kinetic and logistic-kinetic models. Seven metabolites were detected by high-performance liquid chromatography and gas chromatography-mass spectrometry- methyl salicylate, catechol, phthalic acid, salicylic acid, 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid, 3-phenoxybenzaldehyde, and 3-phenoxybenzoic acid (3-PBA). The major Beta-CP metabolite, 3-PBA was further degraded into phenol, benzoic acid, and 4-methylhexanoic acid. BCP-09 also degraded aromatic compounds such as phenol, catechol, and protocatechuic acid. Beta-CP appears to be mainly degraded into 3-PBA, which is continuously degraded into smaller benzene or chain compounds. Thus, strain BCP-09 could form a complete degradation system for Beta-CP and might be considered a promising strain for application in the bioremediation of environments and agricultural products polluted by Beta-CP.

Kinetic analysis on precursors for iturin A production from Bacillus amyloliquefaciens BPD1

In this study, the precursor effect for iturin A production was quantitatively analyzed. A strain identified as Bacillus amyloliquefaciens BPD1 (Ba-BPD1) was selected due to its ability to produce iturin A. The enhancement of iturin A production in a submerged culture was tested using various additives, including palmitic acid, oils, and complex amino acids. Among these, complex amino acids triggered the highest yield at 559 mg/L. The respective amino acids that contribute to the structure of iturin A were used as precursors. In fact, it was found that the addition of l-proline, l-glutamine, l-asparagine and l-serine could improve iturin A yield in the defined medium. However, during the kinetic analysis, all the amino acids exhibited a lower saturation level than l-serine, which exhibited a high saturation level at 1.2% resulting in an iturin A yield of 914 mg/L. In contrast, a negative effect was observed following the addition of l-tyrosine. To analyze the kinetic behavior of l-serine, three kinetic models were adopted: the kinetic order equation, the Langmuir kinetic equation, and a modified logistic equation. The regression results showed that the modified logistic model was the best fit for the kinetic behavior of l-serine as the major precursor, which could be further referred to the biosynthesis pathway of iturin A. Among the proposed processes for iturin A production, this study achieved the highest iturin A levels as a result of the addition of precursors.

Influencia de la luz azul sobre la productividad del cultivo sólido de Ganoderma lucidum

Ganoderma lucidum es un hongo macromiceto reconocido por sus propiedades medicinales y su contenido de compuestos bioactivos que incluyen polisacáridos, triterpenoides, proteínas inmunomoduladoras, entre otros, lo que ha generado un incremento notable en su producción. La mayoría de especies de hongos responden y se adaptan a diversas señales ambientales incluida la luz, que favorece su productividad, tanto en calidad como en cantidad al estar estrechamente relacionada con la formación de cuerpos fructíferos. Por tal razón, el objetivo de este estudio fue evaluar la eficiencia biológica (EB) y la tasa de producción (TP) como parámetros de productividad del cultivo sólido de Ganoderma lucidum bajo irradiación de los sustratos con luz emitida por diodos azules (LED) con dos periodos de foto-estímulo de 12 y 24 h durante todas las fases de cultivo para inducir el crecimiento micelial y la formación de los cuerpos fructíferos. Se aplicaron parámetros convencionales para el crecimiento y desarrollo del hongo en las etapas de producción. Para la formulación de los sustratos, se emplearon residuos agroindustriales y materiales lignocelulósicos. El diámetro de los cuerpos fructíferos sometidos a tratamientos con luz azul fue mayor que los exhibidos a luz blanca fluorescente (Testigo). Los resultados muestran que el cultivo de Ganoderma lucidum con exposición a la luz azul es útil para la inducción de cuerpos fructíferos de alta calidad, logrando una disminución del periodo de fermentación en 16 días para el foto-estímulo de 24 h con EB de 28,04% y TP de 0,64.