Unveiling hidden interactions: Microorganisms, enzymes, and mangroves at different stages of succession in the Shankou Mangrove Nature Reserve, China.

Understanding the interactions between microorganisms, soil extracellular enzymes, and mangroves is crucial for conserving and restoring mangrove ecosystems. However, the unique environments associated with mangroves have resulted in a lack of pertinent data regarding the interactions between these components. Root, stem, leaf, and soil samples were collected at three distinct stages of mangrove succession. Stoichiometry was employed to analyze the carbon, nitrogen, and phosphorus contents of these samples and to quantify extracellular enzyme activities, microbial biomass, and various physicochemical factors in the soil. The results showed that the trends of C, N, and P in the mangrove plants were consistent. Microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and microbial biomass phosphorus (MBP) were the highest in the Kandelia obovate community. Catalase (CAT) and ß-D-G showed the highest content in K. obovate and Bruguiera gymnorrhiza, whereas cellulase showed the opposite trend. Urease was least abundant in the K. obovate community, whereas neutral protease (NPR) and acid phosphatase (ACP) were most abundant. The overall soil environment in mangroves exhibited a state of N limitation, with varying degrees of limitation observed across different succession stages. The demand for P became more intense in the later stages of succession, particularly in the K. obovate and B. gymnorrhiza communities. In conjunction with correlation analysis, it indicated that the input of mangrove plant litter had a significant regulatory influence on the C, N, and P contents in the soil. There was a significant positive correlation between MBC, MBN, and MBP, indicating synergistic effects of C, N, and P on soil microorganisms. Therefore, evaluating the nutrient ratios and sufficiency of mangroves allowed us to comprehensively understand the present environmental conditions. This study aims to develop sustainable management strategies for the conservation and restoration of mangroves.

Cactus polysaccharides enhance preservative effects of ultrasound treatment on fresh-cut potatoes.

The shelf life of fresh-cut fruits and vegetables is affected by microbial growth, enzymatic browning, and loss of flavor. Although ultrasound (US) treatment is often used in the preservation of fresh-cut fruits and vegetables, it has limited antibacterial and preservative effects. Here, we used cactus polysaccharides (CP) to enhance the preservative effect of ultrasound treatment and extended the shelf life of fresh-cut potatoes. The results showed that combined treatment (CP + US) exerted better antimicrobial and anti-browning effects than individual treatments (either US or CP alone). In addition, CP + US has no adverse effect on texture and quality properties, as well as reduced the mobility of internal water. Combination treatment not only significantly decreased the activities of polyphenol oxidase and peroxidase (P < 0.05), but also maintained a high level of phenylalanine ammonia lyase activity and total phenol content during storage. It also maintained the integrity of cell membrane and reduced its permeability by inhibiting the peroxidation of membrane lipids. In addition, CP + US treatment significantly inhibited the activity of antioxidant enzymes and maintained a high DPPH scavenging ability. GC-IMS technology was used to evaluate the flavor of fresh-cut potatoes. The results showed that CP + US treatment reduced the production of a peculiar smell during storage and maintained a good flavor by inhibiting the production of aldehydes. Taken together, these results indicate that the effective preservation method of CP + US treatment can be utilized to increase the shelf life of fresh-cut potatoes.

A multi-CRD C-type lectin gene Cnlec-1 enhance the immunity response in noble scallop Chlamys nobilis with higher carotenoids contents through up-regulating under different immunostimulants.

C-type lectins have a variety of immunological functions in invertebrates. In order to investigate whether C-type lectin gene and carotenoids do have immune influences on noble scallop Chlamys nobilis under pathogen stress, acute challenges lasting 48 h to Vibrio parahaemolyticus, lipopolysaccharide (LPS), polyinosinic polycytidylic acid (Poly I: C), and PBS were conducted in noble scallop with different carotenoids content. A multi-CRD C-type lectin gene called Cnlec-1 was cloned and its transcripts under different challenges were determined. Full length cDNA of Cnlec-1 is 2267 bp with an open reading frame (ORF) of 1845 bp encoding 614 deduced amino acids, containing four carbohydrate recognition domains (CRD1, CRD2, CRD3 and CRD4). Phylogenetic tree analysis showed that CRDs of Cnlec-1 were clustered with CRDs of shellfish C-type lectins, especially closely related to Chlamys farreri and Argopecten irradians CRDs. Cnlec-1 transcripts were detected in hemocytes, mantle, gonad, kidney, intestines, gill and adductor. Compared with PBS control group, Cnlec-1 transcripts were up-regulated in V. parahaemolyticus, LPS and Poly I: C groups. Furthermore, Cnlec-1 transcript levels of Golden scallops were significantly higher than that of Brown ones at 3-48 h (P < 0.05) in V. parahemolyticus groups, at 24 h in LPS groups and at 12-24 h in Poly I: C groups. These results suggesting that Cnlec-1 is an important immune factor involved in the defense against pathogens in the noble scallop, and carotenoids can enhance the immunity of noble scallop through up-regulating Cnlec-1 to different immunostimulants.