Fungal polysaccharides are commonly utilized in the food industry and biomedical fields as a natural and safe immune modulator. Co-culturing is a valuable method for enhancing the production of secondary metabolites. This study used intracellular polysaccharide (IPS) content as a screening index, co-culturing seven different fungi with Sanghuangporus vaninii. The seed pre-culture liquid culture time was selected through screening, and conditions were assessed using single factor experimentation, a Plackett-Burman (PB) design, and response surface methodology (RSM) optimization. RSM optimization was conducted, leading to the measurement of antioxidant capacity. Results indicated that the co-culture of S. vaninii and Pleurotus sapidus exhibited the most effective outcome. Specifically, pre-culturing S. vaninii and P. sapidus seed cultures for 2 days and 0 days, respectively, followed by co-culturing, significantly increased IPS content compared to single-strain culturing. Further optimization of co-culture conditions revealed that yeast extract concentration, liquid volume, and S. vaninii inoculum ratio notably influenced IPS content in the order of yeast extract concentration > liquid volume > S. vaninii inoculum ratio. Under the optimal conditions, IPS content reached 69.9626 mg/g, a 17.04% increase from pre-optimization co-culture conditions. Antioxidant capacity testing demonstrated that co-cultured IPS exhibited greater scavenging abilities for DPPH and ABTS free radicals compared to single strain cultures. These findings highlight the potential of co-culturing S. vaninii and P. sapidus to enhance IPS content and improve antioxidant capacity, presenting an effective strategy for increasing fungal polysaccharide production.

Two new Cortinarius species in subgenus Leprocybe, Cortinarius hengduanensis and C. yadingensis, are proposed based on a combination of morphological and molecular evidence. Cortinarius hengduanensis has distinct olive tinged basidiomata, a squamulose pileus, and small, subglobose to broadly ellipsoid basidiospores, the ITS sequence differs from that of C. flavifolium by at least 28 substitutions and independent positions. Cortinarius yadingensis has a squamulose pileus and subglobose to broadly ellipsoid coarsely verrucose basidiospores, the ITS sequence has at least 11 substitutions and index position deviations from the other members of the Leprocybe section. Both new species were found in mixed forests of southwest China.

Introduction: Fungal secondary metabolites (SMs) have broad application prospects in the food and medicine industries. Co-culturing strategies that simulate natural symbiotic relationships among microorganisms are used to discover and enhance the production of new SMs. We aimed to use the abundant resources of large edible and medicinal fungi to enhance the yield of desired metabolites through co-culture and potentially produce metabolites that cannot be generated in pure cultures.Methods: We assessed the biomass and intracellular polysaccharide (IPS) content of liquid co-cultures of Sanghuangporus vaninii and Pleurotus sapidus. Subsequently, the effect of the liquid co-culture on fungal intracellular metabolites was studied using UPLC-QTOF.Results: Co-culturing of S. vaninii with P. sapidus resulted in significantly increased biomass and IPS content; however, P. sapidus had a significant inhibitory effect on the growth of S. vaninii. Metabolomic data further indicated that amino acid, nucleotide, and glycerophospholipid metabolisms were the primary metabolic pathways affected by symbiosis.Discussion: This study provides insights into fungal interactions and cellular metabolic mechanisms, contributing to the understanding and enhancement of the fungal fermentation potential.

Desiccation tolerance is the ability of orthodox seeds to achieve equilibrium with atmospheric relative humidity and to survive in this state. Understanding how orthodox seeds respond to dehydration is important for improving quality and long-term storage of seeds under low temperature and drought stress conditions. Long-term storage of seeds is an artificial situation, because in most natural situations a seed that has been shed may not remain in a desiccated state for very long, and if dormant it may undergo repeated cycles of hydration. Different types of seeds are differentially sensitive to desiccation and this directly affects long-term storage. For these reasons, many researchers are investigating loss of desiccation tolerance during orthodox seed development to understand how it is acquired. In this study, the orthodox seed proteome response of Fraxinus mandshurica Rupr. to dehydration (to a relative water content of 10%, which mimics seed dehydration) was investigated under four different conditions viz. 20 °C; 20 °C with silica gel; 1 °C; and 1 °C after pretreatment with Ca²⁺. Proteins from seeds dehydrated under different conditions were extracted and separated by two-dimensional difference gel electrophoresis (2D-DIGE). A total of 2919 protein spots were detected, and high-resolution 2D-DIGE indicated there were 27 differentially expressed. Seven of these were identified using MALDI TOF/TOF mass spectrometry. Inferences from bioinformatics annotations of these proteins established the possible involvement of detoxifying enzymes, transport proteins, and nucleotide metabolism enzymes in response to dehydration. Of the seven differentially abundant proteins, the amounts of six were down-regulated and one was up-regulated. Also, a putative acyl-coenzyme A oxidase of the glyoxylate cycle increased in abundance. In particular, the presence of kinesin-1, a protein important for regulation and cargo interaction, was up-regulated in seeds exposed to low temperature dehydration. Kinesin-1 is present in all major lineages, but it is rarely detected in seed desiccation tolerance of woody species. These observations provide new insight into the proteome of seeds in deep dormancy under different desiccation conditions.

Volvariella volvacea, the Chinese mushroom, is a high-temperature grass-rot fungus with great production potential, yet its low yield limits industrial development. Exogenous sodium acetate (NaAc) has been shown to increase yield by promoting indole-3-acetic acid (IAA) synthesis during the primordium stage, but the underlying mechanism remains unclear. In this study, the aldehyde dehydrogenase gene VvALDH, highly expressed at the primordium stage, was cloned and functionally characterized. VvALDH encodes a 1509 bp cDNA with a conserved aldehyde dehydrogenase domain. Using Agrobacterium-mediated transformation, overexpression lines showed a 4.76-fold increase in VvALDH expression, accompanied by higher biomass (38%), yield (83%), and IAA content (34%), while RNAi lines showed opposite trends. These results demonstrate that VvALDH promotes IAA biosynthesis, enhances primordium differentiation, and increases yield. Further analysis revealed its involvement in multiple IAA biosynthetic pathways, including indolepyruvate, tryptamine, and tryptophan side-chain oxidase pathways. This work clarifies the molecular basis of NaAc-mediated yield improvement and provides a theoretical foundation for genetic and cultivation strategies in V. volvacea.

Four new species of Prunulus, found in China—P. applanatus, P. fulvescens, P. fulvipes and P. leptocollus spp. nov.—are described based on morphological and molecular phylogenetic analyses, performed using maximum likelihood (ML) and Bayesian inference (BI) methods on a concatenated dataset of the ITS, rpb1, and tef-1α gene regions. Prunulus applanatus is characterized by a pale grey-brown and applanate pileus with a slight lilac tint, and a distinctly striate margin. Prunulus fulvescens is characterized by a pileus fading from dark brown to yellowish-brown. Prunulus fulvipes is characterized by a pileus with a brown center and a lighter brownish-white margin, and a longer stipe with a yellowish-brown base. Prunulus leptocollus is characterized by pale lilac basidiomata, and cheilocystidia with slightly narrowed necks. Our study provides detailed anatomical illustrations and photographs of fresh basidiocarps from these species. Additionally, six Mycena species of sect. Calodontes—M. brunneocystidiata, M. rosea, M. subbrunnea, M. subpura, M. variispora, and M. violaceardesiaca—are combined with Prunulus based on the results of the phylogenetic analysis.