Bacteria growing inside biofilms are more resistant to hostile environments, conventional antibiotics, and mechanical stresses than their planktonic counterparts. It is estimated that more than 80% of microbial infections in human patients are biofilm-based, and biofouling induced by the biofilms of some bacteria causes serious ecological and economic problems throughout the world. Therefore, exploring highly effective anti-biofilm compounds has become an urgent demand for the medical and marine industries. Marine microorganisms, a well-documented and prolific source of natural products, provide an array of structurally distinct secondary metabolites with diverse biological activities. However, up to date, only a handful of anti-biofilm natural products derived from marine microorganisms have been reported. Meanwhile, it is worth noting that some promising antifouling (AF) compounds from marine microbes, particularly those that inhibit settlement of fouling invertebrate larvae and algal spores, can be considered as potential anti-biofilm agents owing to the well-known knowledge of the correlations between biofilm formation and the biofouling process of fouling organisms. In this review, a total of 112 anti-biofilm, anti-larval, and anti-algal natural products from marine microbes and 26 of their synthetic analogues are highlighted from 2000 to 2021. These compounds are introduced based on their microbial origins, and then categorized into the following different structural groups: fatty acids, butenolides, terpenoids, steroids, phenols, phenyl ethers, polyketides, alkaloids, flavonoids, amines, nucleosides, and peptides. The preliminary structure-activity relationships (SAR) of some important compounds are also briefly discussed. Finally, current challenges and future research perspectives are proposed based on opinions from many previous reviews.

Two fungal strains were isolated from the rhizosphere soil of a Chinese medicinal herb plant, Astragalus polycladus, in northwestern Yunnan, China. Both of them were identified as a new fungal species of Varicosporellopsis based on the evidence of morphology and phylogenetic analysis of ITS, LSU, TUB and ACT sequences data. Phylogenetic analysis of combined ITS and LSU sequence data revealed that strains MTF 7 and KLF 01 belong to the genus Varicosporellopsis with the highest sequence similarity (95.51%) to the type strain V. americana CBS 148257 and formed a sister lineage to V. americana CPC 40768 with high support values (100% ML, 1.00 BI). Morphologically, V. shangrilaensis is characterized by macronematous, branched conidiophores, phialidic conidiogenous cells, reniform macroconidia and spherical microconidia. This new species is the first reported of Varicosporellopsis in China. The morphological description, illustrations and phylogenetic analysis of V. shangrilaensis are provided in this study.

Background/Objectives: Corn steep liquor Powder (CSLP) has previously been reported to promote fruity aroma production by Geotrichum candidum; however, the broader volatile profiles associated with CSLP-based cultivation relative to reference media remain insufficiently characterized. In this study, we compared the volatile metabolite and aroma-related profiles of G. candidum GC1 cultivated in a CSLP-based YMJ medium and two reference media, PDB and GAS. Methods: Using E-nose and HS-SPME-GC-MS, we compared the volatile profiles of G. candidum GC1 cultured in YMJ medium versus PDB and GAS media. Results: A total of 1414 volatile organic compounds (VOCs) belonging to 15 chemical classes were annotated. The YMJ group produced the highest VOC abundance, with significant enrichment of ketones, terpenoids, alcohols, pyrazines and phenols. Key compounds, such as 4-Nonenal (E) and 3(2H)-Furanone dihydro-2-methyl-, contributed fruity, sweet-bread-buttery-nutty notes, respectively, forming the complex floral-fruity-roasted aroma profile of G. candidum GC1 in YMJ medium. Volatile metabolomic analysis showed distinct medium-associated metabolic patterns, with the YMJ medium displaying a more diverse aroma-related volatile profile than the reference media under the conditions tested. Conclusions: The CSLP-based YMJ medium supported a distinct and relatively complex volatile profile in G. candidum GC1. These results support the potential use of CSLP-containing media in flavor-oriented fermentation design.