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Green tides caused by Ulva prolifera occur annually in the Yellow Sea, potentially influencing the marine microorganisms. Here, we focused on the variations in marine bacterial and archaeal communities during an U. prolifera green tide in coastal Qingdao areas with Illumina high-throughput sequencing analysis. Our results revealed that the diversity and structure of bacterial and archaeal communities, as well as the organization and structure of microbial co-occurrence networks, varied during the green tide. The decline phase may be favorable to the bacterial and archaeal diversity and richness. The bacterial community, as well as the archaeal community, showed clear variations between the outbreak and decline phases. A simpler and less connected microbial co-occurrence network was observed during the outbreak phase compared with the decline phase. Flavobacteriales and Rhodobacterales separately dominated the bacterial community during the outbreak and decline phase, and Marine Group II (MGII) dominated the archaeal community during the green tide. Combined with microbial co-occurrence network analysis, Flavobacteriales, Rhodobacterales and MGII may be important organisms during the green tide. Temperature, chlorophyll a content and salinity may have an important impact on the variations in bacterial and archaeal communities during the green tide. [ABSTRACT FROM AUTHOR]

Although Alteromonas is ubiquitous in the marine environment, very little is known about Alteromonas phages, with only ten, thus far, being isolated and reported on. In this study, a novel double-stranded DNA phage, Alteromonas phage P24, which infects Alteromonas macleodii, was isolated from the coastal waters off Qingdao. Alteromonas phage P24 has a siphoviral morphology, with an icosahedral head, 61 ± 1 nm in diameter, and a tail length of 105 ± 1 nm. Alteromonas phage P24 contains lipids. It has an optimal temperature and pH for growth of 20℃ and 5–7, respectively. A one-step growth curve shows a latent period of 55 min, a rise period of 65 min, and an average burst size of approximately 147 virions per cell. Alteromonas phage P24 has the genome of 46,945 bp with 43.80% GC content and 74 open reading frames (ORFs) without tRNA. The results of the phylogenetic tree, based on the mcp and terL genes, show that Alteromonas phage P24 is closely related to Aeromonas phage phiARM81ld. Meanwhile, phylogenetic analysis based on the whole genome of P24 indicates that it forms a unique viral sub-cluster within Siphoviridae. This study contributes to the understanding of the genomic characteristics and the virus-host interactions of Alteromonas phages. [ABSTRACT FROM AUTHOR]

Two novel Vibrio phages, LP.1 and LP.2 that infected Vibrio maritimus R-40493, were isolated from surface seawater in Qingdao coastal area by the double-agar layer method. Morphological analysis by transmission electron microscope showed that the two phages displayed head–tail structures with icosahedral heads of 62.37 and 54.00 nm in diameter and long non-contractile tails of 119.00 and 105.20 nm in length, respectively, and can be grouped into the Siphoviridae family. Thermal and pH sensitivity tests exhibited that LP.1 was stable at temperature ranging from − 20 to 65 °C and at pH ranging from 5 to 12, and LP.2 showed vitality over a wider range of temperature (− 20–75 °C) and pH (3–12). Both LP.1 and LP.2 contained linear and double-stranded DNA genomes with a length of 46,791-bp and 37,128-bp, respectively. The genome of both phages can be classified into four functional groups, including DNA replication and regulation, phage packaging, phage structure, and additional function. The bioinformatic analysis demonstrated that the Vibrio phages LP.1 and LP.2 are novel phages. By conducting morphological, biochemical, and genomic analysis, our study provides useful information for further research on the interaction between Vibrio phages and their host. [ABSTRACT FROM AUTHOR]

[Display omitted] • Construction of an interfacial steam generator by using nanocellulose extracted from marine biomass. • Rational fabrication of nanocellulose-based aerogels as structural elements. • Realization of a 3D monolithic interfacial steam generator for efficient and durable solar evaporation. Solar-driven interfacial evaporation is an emerging and sustainable technology with growing potential for applications in water distillation and desalination. Despite the ongoing progress in clean water production, the high cost, delicate structures, leaching and disposal of synthetic materials remain the major roadblocks toward large-scale and real-world applications. Herein, nanocellulose (NC) is successfully extracted from abundant, inexhaustible and biodegradable biomass Ulva (Enteromorpha) prolifera that collected from the coast of Qingdao, China. Incorporation of polyvinyl alcohol (PVA) into the NC scaffolds and subsequent cross-linking endow the composite aerogels with efficient water diffusion, enhanced mechanical strength and good deformation resistance. The cross-linked composite aerogels can serve as main structural elements and integrate a monolithic, self-floating and durable steam generator. Under one sun, the good water evaporation rate of 1.4 kg m−2 h−1 is among the best-performing interfacial steam generators constructed by using cellulose-based materials as structural components. This study demonstrates a new concept of using marine (blue) biomass-derived NC as crude material and building block to construct high-performance and durable interfacial steam generators, synergistically considering clean water production and sustainability of marine ecosystems. [ABSTRACT FROM AUTHOR]

• Phage AL can provide information for study of interaction between marine phage and host. • The order of the functional genes in phage AL is highly conserved and follows the common pattern used by siphovirus. • Pseudoalteromonas phage AL shows genetic plasticity and flexibility in evolution. Although Pseudoalteromonas is an abundant, ubiquitous, marine algae-associated bacterial genus, there is still little information on their phages. In the present study, a marine phage AL, infecting Pseudoalteromonas marina , was isolated from the coastal waters off Qingdao. The AL phage is a siphovirus with an icosahedral head of 53 ± 1 nm and a non-contractile tail, length of 99 ± 1 nm. A one-step growth curve showed that the latent period was approximately 70 min, the rise period was 50 min, and the burst size was 227 pfu/cell. The genome sequence of this phage is a 33,582 bp double-stranded DNA molecule with a GC content of 40.1 %, encoding 52 open reading frames (ORFs). The order of the functional genes, especially those related to the structure module, is highly conserved and basically follows the common pattern used by siphovirus. The stable order has been formed during the long-term evolution of phages in the siphovirus group, which has helped the phages to maintain their normal morphology and function. Phylogenetic trees based on the major capsid protein (mcp) and genome-wide sequence have shown that the AL phage is closely related to four Pseudoalteromonas phages, including PHS21, PHS3, SL25 and Pq0. Further analysis using all-to-all BLASTP also confirmed that this phage shared high sequence homology with the same four Pseudoalteromonas phages, with amino acid sequence identities ranging from 44 % to 71 %. In particular, their similarity in virion structure module may imply that these phages share common assembly mechanism characteristics and infection pathways. Pseudoalteromonas phage AL not only provides basic information for the further study of the evolution of Pseudoalteromonas phages and interactions between marine phage and host but also helps to explain the unknown viral sequences in the metagenomic databases. [ABSTRACT FROM AUTHOR]