A study of mycelial growth and exopolysaccharide production from a submerged culture of Mycoleptodonoides aitchisonii in an air-lift bioreactor

Enhancing high-efficiency breeding and microbial microdroplet cultivation techniques for Ganoderma lucidum

Ganoderma lucidum is known for its bioactive compounds, such as polysaccharides and triterpenoids, which are crucial in food and medicine. However, liquid fermentation encounters challenges in terms of strain differentiation and stability. In this research, we employed atmospheric room temperature plasma mutation and a microbial microdroplet culture system to identify strains with enhanced biomass and triterpenoid production. The three mutant strains, YB05, YB09, and YB18, exhibited accelerated growth rates and antagonized the initial strain G0023 more effectively than the controls. Notably, YB18 displayed the fastest growth, with a 17.25% increase in colony radius. Shake flask cultivation demonstrated that, compared with the initial strain, YB05 and YB18 had 26.33% and 17.85% greater biomass, respectively. Moreover, the triterpenoid production of YB05 and YB18 surpassed that of the control by 32.10% and 15.72%, respectively, as confirmed by colorimetric detection. Importantly, these mutant strains remained stable for five generations. This study revealed a comprehensive screening system utilizing atmospheric pressure, room temperature plasma mutation technology and microbial droplet cultivation. This innovative approach offers a promising pathway for obtaining advantageous Ganoderma strains for liquid fermentation. The methodology of atmospheric room temperature plasma mutation and microbial microdroplet culture systems is detailed for better comprehension.

A novel oligosaccharide isolated from Hericium erinaceus and its protection against LPS-induced Caco-2 cells via the TLR4/NF-κB pathway

A novel oligosaccharide showed that protection against LPS-induced Caco-2 cells was purified from the mycelium of Hericium erinaceus (HE). WEP-1 is mainly composed of neutral monosaccharides with molecular weight of 4,010 Da and of mannose, glucose, and galactose in a molar ratio of 1.2:16.9:1. The structure of WEP-1 includes α-D-Glc (1 → 3) and β-D-Gal (1 → 3) as the backbone with β-D-Glc (1 → 3) as branches attached to the C-4 position and β-D-Man as a terminal residue. The oligosaccharide reduced acetic acid-induced colonic mucosa injury in rats. It also showed significant protection against LPS-induced Caco-2 cells via the TLR4/NF-κB pathway. PRACTICAL APPLICATIONS: In the study, the oligosaccharide from HE has the potential to be developed into functional foods or medicines for the treatment of intestinal diseases. The protection against LPS-induced Caco-2 cells via the TLR4/NF-κB pathway may be a key target for the pharmacological activity of HE.

A unique polysaccharide purified from Hericium erinaceus mycelium prevents oxidative stress induced by H2O2 in human gastric mucosa epithelium cell

Hericium erinaceus (HE) has been used both as a traditional Chinese medicine and home remedy for treatment of gastric and duodenal ulcers and gastritis. EP-1, a purified polysaccharide isolated from HE mycelium, has recently been identified as the active component responsible for HE anti-gastritis activity. Because oxidative stress has been implicated as a pathogenic cause of gastritis and gastric ulcers, EP-1 antioxidant properties were systematically examined in vitro using the human gastric mucosal epithelial cell line, GES-1. Results showed that EP-1 possessed higher oxygen radical absorbance capacity (ORAC) and 2-3 times higher ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals than a hot water extract of commercially available HE fruiting body. A crude mycelial polysaccharide (CMPS) extract of HE, from which EP-1 was purified, showed slightly stronger radical scavenging activity and ORAC than EP-1, with the exception of DPPH-scavenging activity. Antioxidant activities of these extracts were further studied using hydrogen peroxide (H2O2)-abused GES-1 cells; EP-1 dose-dependently preserved cell viability of abused cells as assessed via MTT assay. Moreover, FACS analysis revealed that EP-1 prevented H2O2-induced apoptotic cell death by inhibiting activation of apoptotic cellular signals within mitochondria-dependent apoptotic pathways. CMPS also prevented H2O2-induced oxidative stress, but to a lesser degree than did EP-1, even though CMPS exhibited comparable or stronger in vitro antioxidant activity than did EP-1.

A polysaccharide from cultured mycelium of Hericium erinaceus and its anti-chronic atrophic gastritis activity

A polysaccharide named EP-1 was found by screening cultured mycelium of Hericium erinaceus, which was extracted and subjected to precipitation with ethanol, hollow-fiber ultrafiltration and ion-exchange chromatography. The polysaccharide has a molecular weight of approximately 3100Da and is composed of glucose, mannose and galactose, thus being a heteroglycan. EP-1 has a backbone of α-d-Glc(1→3) and β-d-Glc(1→3). The β-d-Glc(1→3) and α-d-Gal-(1→3) were regarded as branches attached to the C-4 position. The α-d-Man was regarded as a terminal residue. The anti-CAG activity was evaluated in experimental systems using a cell model for identification. The polysaccharide significantly inhibited the growth of MC cells obtained from human gastric mucosa epithelium (GES-1) cells transformed by MNNG, which were used as a chronic atrophic gastritis cell model. It also interfered with the MC cells by inducing cell cycle arrest. Thus, EP-1 shows potential for the development of new functional foods and drugs.

Nutrient improvement for simultaneous production of exopolysaccharide and mycelial biomass by submerged cultivation of Schizophyllum commune AGMJ-1 using statistical optimization

Exopolysaccharides (EPS) of fungal origin have attracted special attention from researchers due to their multifarious applications in the food and pharmaceutical industries. In the present study, optimization of the process parameters for the production of exopolysaccharide by Schizophyllum commune AGMJ-1 was studied using one factor at a time (OFAT) method, Plackett–Burman design (PBD) and response surface methodology (RSM). OFAT method revealed xylose and yeast extract to be the most effective carbon and nitrogen sources and pH 5.3 as an optimum for maximum EPS production. Xylose, yeast extract and KCl were screened as statistically significant variables for EPS production using PBD. RSM based on the central composite design estimated that maximum EPS (4.26 g L⁻¹), mycelial biomass (14 g L⁻¹) and specific yield (0.45 g g⁻¹) were obtained when concentration of xylose, yeast extract and KCl were set at 2.5 g % (w/v), 0.83 g % (w/v) and 6.53 mg % (w/v), respectively, in the production medium.