Inflammation is the body’s defense reaction in response to stimulations and is the basis of various physiological and pathological processes. However, chronic inflammation is undesirable and closely related to the occurrence and development of diseases. The ocean gives birth to unique and diverse bioactive substances, which have gained special attention and been a focus for anti-inflammatory drug development. So far, numerous promising bioactive substances have been obtained from various marine organisms such as marine bacteria and fungi, sponges, algae, and coral. This review covers 71 bioactive substances described during 2015–2020, including the structures (65 of which), species sources, evaluation models and anti-inflammatory activities of these substances. This review aims to provide some reference for the research progress of marine-organism-derived anti-inflammatory metabolites and give more research impetus for their conversion to novel anti-inflammatory drugs.

Surfactin is widely used in the petroleum extraction, cosmetics, biopharmaceuticals and agriculture industries. It possesses antibacterial and antiviral activities and can reduce interfacial tension. Bacillus are commonly used as production chassis, but wild-type Bacillus subtilis 168 cannot synthesise surfactin. In this study, the phosphopantetheinyl transferase (PPTase) gene sfp* (with a T base removed) was overexpressed and enzyme activity was restored, enabling B. subtilis 168 to synthesise surfactin with a yield of 747.5 ± 6.5 mg/L. Knocking out ppsD and yvkC did not enhance surfactin synthesis. Overexpression of predicted surfactin transporter gene yfiS increased its titre to 1060.7 ± 89.4 mg/L, while overexpression of yerP, ycxA and ycxA-efp had little or negative effects on surfactin synthesis, suggesting YfiS is involved in surfactin efflux. By replacing the native promoter of the srfA operon encoding surfactin synthase with three promoters, surfactin synthesis was significantly reduced. However, knockout of the global transcriptional regulator gene codY enhanced the surfactin titre to 1601.8 ± 91.9 mg/L. The highest surfactin titre reached 3.89 ± 0.07 g/L, with the yield of 0.63 ± 0.02 g/g DCW, after 36 h of fed-batch fermentation in 5 L fermenter. This study provides a reference for further understanding surfactin synthesis and constructing microbial cell factories.

This study was performed to investigate the fermentation efficiency of Lactobacillus acidophilus and compare the effects of dietary soybean meal (SM) or L. acidophilus-fermented SM (LASM) on turbot. Two hundred and seventy juvenile turbots ( ) were randomly divided into three treatments fed with a fishmeal-based diet (CNT) and two experimental diets with 45% fishmeal protein replaced by SM or LASM for 8 weeks. The results showed that fermentation significantly improved the essential amino acid profile, increased the lactic acid content, and reduced the antinutritional factor level in SM. Inferior growth of fish was observed in the SM group after the feeding trial, while the LASM group exhibited comparable performance to the CNT group. Activities of intestinal digestive enzymes (trypsin and diastase) and immune-related enzymes (alkaline phosphatase, acid phosphatase, and lysozyme) decreased significantly in the SM group, while no significant reduction was found in the LASM group compared to the CNT group. Dietary LASM alleviated SM-induced intestinal pathological disruption with higher villus and normal lamina propria width. Dietary LASM positively regulated the intestinal microbiota, making the overall profile more coherent with that in the CNT group. Spearman’s correlation analysis revealed that the altered intestinal microbiota was closely linked to the digestive enzyme activities. Collectively, this study indicated that L. acidophilus fermentation significantly improved the nutritional quality of SM and relieved SM-induced adverse effects on turbot, in terms of growth, intestinal digestive and immune-related enzyme activities, morphology, and microbiota.

Background: Continuous cropping challenges constrain the development of agriculture. Three main obstacles limit continuous cropping: autotoxicity of plant allelochemicals, deterioration of physicochemical characteristics of soil, and microflora imbalance. Plant-derived phenolic acids can cause autotoxicity, which is considered the main factor mediating continuous cropping obstacles. Reducing the phenolic acids in continuous cropping soils can decrease the autotoxicity of phenolic acids and ameliorate continuous cropping obstacles. Therefore, it is important to study the microbial resources that degrade allelochemical phenolic acids. Thus, the bacterial strain V4 that can degrade phenolic acids was isolated, identified, and genomically analyzed. Results: Strain V4 isolated from strawberry soil using vanillic acid-mineral agar was identified as a Gram-negative short rod bacterium. Subsequent 16S rRNA phylogenetic analysis revealed that V4 clustered with members of the genus Sphingobium. The most closely related species were Sphingobium lactosutens DS20^T (99% similarity) and Sphingobium abikonense NBRC 16140^T (97.5% similarity). V4 also shared > 95% sequence similarity with other members of Sphingobium, so Sphingobium sp. V4 was named accordingly. Biochemical tests revealed that the biochemical characteristics of Sphingobium sp. V4 were similar to its most similar strains except for some properties. Sphingobium sp. V4 effectively degraded vanillic acid, ferulic acid, p-coumaric acid, p-hydroxybenzoic acid, and syringic acid. V4 grew best at the conditions of 30 °C, pH 6.0–7.0, and 0–0.05% NaCl. 500 mg/L vanillic acid was completely degraded by V4 within 24 h under the optimal conditions. Whole genome analysis showed that Sphingobium sp. V4 contained one chromosome and three plasmids. Two genes involved in vanillic acid degradation were found in the V4 genome: the gene encoding vanillate O-demethylase oxidoreductase VanB on the chromosome and the gene encoding vanillate monooxygenase on a large plasmid. The organization of vanillate catabolic genes differed from the adjacent organization of the genes, encoding vanillate o-demethylase VanA and VanB subunits, in Pseudomonas and Acinetobacter. Conclusions: The isolated bacterium Sphingobium sp. V4 degraded multiple phenolic acids. Its properties and genome were further analyzed. The study provides support for further investigation and application of this phenolic acid-degrading microorganism to alleviate continuous cropping obstacles in agriculture.

The focus of people on the yield of aquatic products has gradually shifted to superior quality. Astaxanthin is well‐known for its superior antioxidant capacity, while research on its regulatory effect on muscle quality is limited. This study aims to investigate whether dietary Phaffia rhodozyma ‐synthesized 3S, 3′S‐astaxanthin (L‐AST) could promote the body coloration and muscle quality of Litopenaeus vannamei . Experimental diets with L‐AST levels of 0, 30, 60, and 90 mg/kg were fed to L. vannamei (IBW: 2.72 ± 0.03 g) for 8 weeks. The results revealed that the shrimp fed L‐AST diets presented better body coloration with decreased L ^∗ values whereas increased a ^∗ values and possessed higher levels of muscle astaxanthin. Dietary supplementation with 60 mg/kg L‐AST significantly enhanced muscle texture (hardness, chewiness, resilience, and gumminess), which could be attributed to an increase in alkaline‐insoluble collagen content and a decrease in myofiber diameter. Interestingly, dietary supplementation with 60 or 90 mg/kg L‐AST markedly increased the content of glycine (a sweet amino acid) and total flavor amino acid (glutamic acid, aspartate, alanine, glycine). Further study showed that dietary supplementation with 60 or 90 mg/kg L‐AST significantly improved free fatty acid profile by increasing contents of some monounsaturated fatty acids (C17:1n7, C18:1n9t and C24:1n9) and polyunsaturated fatty acids (C20:02 and C22:6n3). Taken together, dietary P. rhodozyma ‐synthesized L‐AST considerably promoted muscle quality in L. vannamei by promoting histological and texture properties, elevating alkaline‐insoluble collagen content while improving the profile of free amino acids and fatty acids.