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The coastal areas of the Red Sea within Saudi Arabia have a wide diversity of marine soft corals harboring many symbiotic bacteria that could present a potential source of many antibacterial metabolites. This study focused on the molecular characterization of antibiotic-producing bacteria associated with soft corals and investigated the influence of culture conditions on the production of their antibacterial extracts. Two soft coral samples were collected offshore from Yanbu City and identified as genus Sarcophyton. Screening for antibiotic-producing bacterial symbionts uncovered nine isolates with a wide inhibitory spectrum against gram-positive and negative bacteria. Phylogenetic analysis of the bioactive bacterial symbionts 16S rRNA gene sequences revealed the prevalence of gram-negative bacteria with seven isolates all belonging to class γ-proteobacteria. The remaining two isolates were represented within class firmicutes and actinobacteria. Eight isolates were grouped perfectly with their best matches. While the remaining ninth isolate was phylogenetically separated from all the species within the Photobacterium genus, suggesting that it could be a novel species. The optimum antibacterial compounds production was obtained in minimal media, at a temperature range of 25–28 °C, pH 7 and 100–150 rev/min agitation during 24–48 h of the incubation period, with moderate to high degree of thermal stability. [ABSTRACT FROM AUTHOR]

Organic carbon source plays a fundamental function in the metabolism and production of photosynthetic microorganisms. Herein, this study explored the effects of carbon source additions (glucose, sucrose and sodium acetate) on growth and biochemical components of the economic cyanobacterium Nostoc sphaeroides. The effects of sucrose and sodium acetate on its metabolomics changes, as well as the diversity and community composition of symbiotic bacteria, were analyzed. Results showed that sucrose noticeably enhanced the relative growth rate of N. sphaeroides. The content of phycocyanin was significantly greater under sodium acetate than under other carbon sources. Some metabolites associated with amino acid biosynthesis was significantly enriched under sodium acetate, implying its critical role in phycocyanin synthesis. Sodium acetate had a significant impact on the diversity and community composition of symbiotic bacteria. Additionally, partial symbiotic bacteria were shown to be involved in the amino acid metabolism of N. sphaeroides. These findings provided valuable insights into the mechanisms of N. sphaeroides on its metabolic responses to carbon source changes and the synergy of its symbiotic bacteria, contributing to the establishment of effective carbon source supply strategies for artificial cultivation and resource restoration. • Organic carbon is critical compound for the growth and metabolism of N. sphaeroides. • Organic carbon visibly affected symbiotic bacteria diversity and composition. • The biomass of N. sphaeroides was markedly enhanced by sucrose addition. • Acetate sodium significantly promoted the accumulation of phycocyanin. • Symbiotic bacteria were likely to be involved in the metabolism of amino acids. [ABSTRACT FROM AUTHOR]

Faba bean belongs to the most important legumes in Poland. This results from the high yield potential, significant role in crop rotation, and the possibility of using this crop in animal nutrition. The aim of this study was to evaluate the effect of seed inoculation (Rhizobium leguminosarum bv. viciea) and initial nitrogen dose on the faba bean yield quantity and quality. A controlled field experiment was carried out in the years 2019-2021, on a field of the Podkarpackie Agricultural Advisory Centre (PODR) in Boguchwała. The faba bean variety Fernando was cultivated. A one-factor experiment was set up with four replicates in a randomized block design. Moisture and thermal conditions varied in the study years and influenced the faba been seed yield. It was shown that inoculation (B), initial nitrogen fertilization (C), and both treatments applied together (B+C) increased seed yield by 0.17, 0.14, and 0.22 t ha-1, respectively, compared to the control (A). Of the yield components, the number of pods per plant and the thousand-seed weight (TSW) were significantly modified. The combined use of the inoculant and initial nitrogen dose (B+C) increased the protein content and decreased the fiber content in relation to control seeds (A). Nitrogen fertilization applied alone or in combination with the inoculant increased the content of P, K, and Fe in seeds as compared with the control (A) and the treatment with the inoculant (B). The highest content of Mn was determined in control seeds (A), while its content after the combined use of inoculation and nitrogen fertilization (B+C) was significantly lower. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three new Simkaniaceae and one new Rhabdochlamydiaceae draft genome assembled. • Clarification of phylogeny for existing Parachlamydiales. • Links genomic diversity and metagenomic data to associated eukaryotic host. Chlamydiota are an ancient and hyperdiverse phylum of obligate intracellular bacteria. The best characterized representatives are pathogens or parasites of mammals, but it is thought that their most common hosts are microeukaryotes like Amoebozoa. The diversity in taxonomy, evolution, and function of non-pathogenic Chlamydiota are slowly being described. Here we use data mining techniques and genomic analysis to extend our current knowledge of Chlamydiota diversity and its hosts, in particular the Order Parachlamydiales. We extract one Rhabdochlamydiaceae and three Simkaniaceae Metagenome-Assembled Genomes (MAGs) from NCBI Short Read Archive deposits of ciliate and algal genome sequencing projects. We then use these to identify a further 14 and 8 MAGs respectively amongst existing, unidentified environmental assemblies. From these data we identify two novel clades with host associated data, for which we propose the names " Sacchlamyda saccharinae" (Family Rhabdochlamydiaceae) and " Amphrikana amoebophyrae" (Family Simkaniaceae), as well as a third new clade of environmental MAGs " Acheromyda pituitae " (Family Rhabdochlamydiaceae). The extent of uncharacterized diversity within the Rhabdochlamydiaceae and Simkaniaceae is indicated by 16 of the 22 MAGs being evolutionarily distant from currently characterised genera. Within our limited data, there was great predicted diversity in Parachlamydiales metabolism and evolution, including the potential for metabolic and defensive symbioses as well as pathogenicity. These data provide an imperative to link genomic diversity in metagenomics data to their associated eukaryotic host, and to develop onward understanding of the functional significance of symbiosis with this hyperdiverse clade. [ABSTRACT FROM AUTHOR]

Rhizobia are the symbiotic bacteria found in the soil which have potential ability to convert atmospheric di-nitrogen into usable form. A total of ten rhizobial strains were isolated from the root nodules of a medicinal legume Mucuna pruriens (L.) that commonly grow in the foothills of the Himalaya. All the ten strains isolated from different locations of same area were morphologically, biochemically and physiologically characterized based on the Bergey's Manual of systematic Bacteriology. They were tested for the antibiotics sensitivity. The isolates showed high sensitivity to amoxicillin and least to erythromycin. Authentication test was done in eleven legumes but shown nodulations only in Trigonella foenum-graecum, Mucuna pruriens and Medicago sativa. The morphology, physiology, biochemical and infection test studies carried out justifies that the bacteria isolated belonged to the species of Rhizobium meliloti. [ABSTRACT FROM AUTHOR]

While genetically modified (GM) crops bring economic benefits to human beings, their impact on non-target organisms has become an important part of environmental safety assessments. Symbiotic bacteria play an important role in eukaryotic biological functions and can adjust host communities to adapt to new environments. Therefore, this study examined the effects of Cry1B protein on the growth and development of non-target natural enemies of Pardosa astrigera (L. Koch) from the perspective of symbiotic bacteria. Cry1B protein had no significant effect on the health indicators of P. astrigera (adults and 2nd instar spiderlings). 16S rRNA sequencing results revealed that Cry1B protein did not change the symbiotic bacteria species composition of P. astrigera , but did reduce the number of OTU and species diversity. In 2nd instar spiderlings, neither the dominant phylum (Proteobacteria) nor the dominant genus (Acinetobacter) changed, but the relative abundance of Corynebacterium-1 decreased significantly; in adult spiders, the dominant bacteria genera of females and males were different. The dominant bacterial genera were Brevibacterium in females and Corynebacterium-1 in males, but Corynebacterium-1 was the dominant bacteria in both females and males feeding on Cry1B. The relative abundance of Wolbachia also increased significantly. In addition, bacteria in other genera varied significantly by sex. KEGG results showed that Cry1B protein only altered the significant enrichment of metabolic pathways in female spiders. In conclusion, the effects of Cry1B protein on symbiotic bacteria vary by growth and development stage and sex. [Display omitted] • Bioassay results showed no effect of Cry1B on P. astrigera growth and reproduction. • Cry1B protein did not change the symbiotic bacteria species composition of P. astrigera , but reduce the number of OTU and species diversity. • Feeding on Cry1B protein had effects on relative abundance of microbes. • Cry1B altered only the significant enrichment of females in the metabolic pathway. [ABSTRACT FROM AUTHOR]

Aphis gossypii is one of the most economically important insect pests for agriculture worldwide. Aphids have developed symbiotic associations with bacterial species, which has led to morphological and molecular differences, such as body color and insecticide resistance. Adults and 3rd instar nymphs of a laboratory-selected spirotetramat-resistant strain of cotton aphid presented 579-fold and 15-fold higher resistance to spirotetramat, respectively, than a susceptible strain (Pan et al., 2015; Peng et al., 2016). In this study, we found that antibiotics, especially ampicillin and tetracycline, increased spirotetramat toxicity in resistant aphids. We also characterized all of the bacterial endosymbionts in these two clones by sequencing the 16S rRNA genes of the endosymbiont. The total reads could be clustered into 3534 operational taxonomic units (OTUs) that showed 97% similarity and belonged to six abundant phyla. Proteobacteria and Firmicutes dominated in the two strains, and the most abundant families were Enterobacteriaceae , Lactobacillaceae and Rhodobiaceae . The genera Arsenophonus , Anderseniella , Buchnera and Lactobacillus were most abundant in the susceptible strain, whereas a significant decrease in abundance of Anderseniella and a great increase in abundance of Arsenophonus and Lactobacillus were observed in the resistant strain. Certain identified species had low sequence similarity to the reported species, which indicates the possibility of novel taxa. The type and abundance of different bacterial groups varied significantly between the two strains. The insecticide selection pressure could be the reason for the observed shift in the bacteria groups. These results increase our understanding of the symbiotic relationships between bacteria and their hosts under insecticide stress and provide clues for the development of potential control techniques against this cotton aphid. [ABSTRACT FROM AUTHOR]

Unusually large amounts of marine snow, including Extracellular Polymeric Substances (EPS), were formed during the 2010 Deepwater Horizon oil spill. The marine snow settled with oil and clay minerals as an oily sludge layer on the deep sea floor. This study tested the hypothesis that the unprecedented amount of chemical dispersants applied during high phytoplankton densities in the Gulf of Mexico induced high EPS formation. Two marine phytoplankton species ( Dunaliella tertiolecta and Phaeodactylum tricornutum ) produced EPS within days when exposed to the dispersant Corexit 9500. Phytoplankton-associated bacteria were shown to be responsible for the formation. The EPS consisted of proteins and to lesser extent polysaccharides. This study reveals an unexpected consequence of the presence of phytoplankton. This emphasizes the need to test the action of dispersants under realistic field conditions, which may seriously alter the fate of oil in the environment via increased marine snow formation. [ABSTRACT FROM AUTHOR]

This study is aimed at searching for microalgae growth-promoting bacteria (MGPB) that can promote Chlorella growth in adverse environments. Fifty strains of symbiotic bacteria were isolated from four Chlorella species and identified by 16S rRNA gene sequences. Function screening and binary culture experiments classified forty-three of these strains as MGPB. In adversities (iron deficiency, high salinity, or unsuitable seawater environment), a significant increase in growth parameters was observed for MGPB-treated microalgae compared to the uninoculated control, and Dinoroseobacter shibae was the most effective strain. Using inorganic nutrient-rich and microalgae-free seawater (S-seawater and Q-seawater) as media, aseptic Chlorella thrived in Q-seawater but could not grow in S-seawater, which was relatively rich in Alteromonas and Vibrio. However, Chlorella could thrive when 250 μL /L D. shibae (OD600 = 0.1) was added into S-seawater. Chlorella growth rates in S- and Q-seawater inoculated with D. shibae were not significantly different (P > 0.05), but were all significantly (P < 0.05) lower than in Q-seawater without D. shibae addition. 16S rRNA gene profiling revealed that similar phycosphere bacterial communities emerged in microalgae grown in Q- and S-seawater supplemented with D. shibae , manifested by recruiting more Rhodobacteriaceae (such as Ruggieella sp.) and fewer Pseudomonadaceae (such as Pseudomonas sp.). These results indicate that phycosphere bacterial communities could be modified by symbiotic MGPB addition. MGPB inoculation showed a positive effect on the growth of Chlorella under stress conditions but might be invalid under favorable environments. These also suggest that these isolated MGPBs, specifically D. shibae , can be exploited as a bioinoculant for the initial establishment of microalgal communities in adverse environments. [Display omitted] • Isolation and identification of 43 MGPB strains from Chlorella symbionts • Inoculating a minute quantity of D. shibae helped Chlorella thrive in adversities. • D. shibae addition caused more Rhodobacteraceae and fewer Pseudomonadaceae in phycosphere. • Phycosphere microbiomes can be modified by MGPB addition. [ABSTRACT FROM AUTHOR]

In this study, 23S rDNA from Arsenophonus and wsp gene from Wolbachia were amplified by PCR method using specific primers to study their symbiosis in Chilo suppressalis from 20 locations of China. The results indicated that Arsenophonus and Wolbachia infection rates differed widely in C. suppressalis populations. The infection rates of Arsenophonus ranged from 5. 0% to 50. 0% in five geographical populations from Harbin, Huishui, Jilin, Nanyang, and Yangzhou. Wolbachia ranged from 25. 0% to 40. 0% in three geographical populations from Hanzhong, Nanning, and Yangzhou. Their symbiosis was not observed in C. suppressalis of other locations. The sequences of 23S rDNA gene which named csArs were exactly the same in the five populations. However, the sequences of wsp from the three strains of Wolbachia showed wChisup1 belonged to supergroup A, wChisup5 and wChisup6 belonged to supergroup B. The results showed the strains of Arsenophonus from C. suppressalis of the five different locations were identical, whereas the strains of Wolbachia were phylogenetically diverse. The phylogenetic analysis indicated that 23S rDNA and wsp sequences found in C. suppressalis were exactly the same with or very closely related to relevant sequences in other species. [ABSTRACT FROM AUTHOR]

Abstract: The oral toxicity of the symbiotic bacteria Photorhabdus temperata was investigated in various developmental stages of Paratlanticus ussuriensis. Supernatants of Photorhabdus culture medium were mixed into an artificial diet, which was fed to various stages of immature nymphs and adults of P. ussuriensis. Mortality was highest in the first instar nymph but decreased in older stages of immature nymphs. Adult females were not killed upon oral ingestion of P. ussuriensis, but their fecundity was significantly inhibited to 29.3% of that of control. In addition, the effects of oral ingestion of the symbiont culture media on the expression rates of three heat shock protein 70 genes (hsp70a, hsp70b, and hsp70c) in third instar nymphs of P. ussuriensis were determined by quantitative real-time RT-PCR analysis. There were no significant changes in expression levels in comparison with control, which suggests that hsp genes may not be associated with the mechanism of Photorhabdus toxicity. Our results imply that Photorhabdus culture media is highly effective in killing younger immature nymphs and also suppressing adult reproduction of P. ussuriensis. [Copyright &y& Elsevier]

Abstract: Two anthraquinones were isolated from the symbiotic bacteria Photorhabdus temperata of entomopathogenic nematodes Heterorhabditis spp. by repeated column chromatography. They were abundantly present in the culture medium and identified as 1,3-dimethoxy-8-hydroxy-9,10-anthraquinone and 3-methoxychrysazine by spectral analysis. The isolated anthraquinones were highly lethal to larvae of Culex pipiens pallens. Our results suggest that anthraquinones might be useful as biopesticides for the biological control of mosquitoes. [Copyright &y& Elsevier]

Abstract: The oral toxicity of 5 Photorhabdus spp. strains collected in different regions of Korea was determined in the larvae of Plodia interpunctella, Galleria mellonella, Lucilia caesar, and Culex pipiens pallens. When diet or water containing culture media containing 1 of the 5 different strains was ingested by immature insects, the first instar larvae of both G. mellonella and L. caesar and young larvae of C. pipiens pallens died within 3–5days after treatment. However, mortality of P. interpunctella neonate larvae was slightly slower and reached 94.4%–100% within 7days after treatment. The mortality rate of a control group given a diet containing water, the medium without cultured bacteria, or Escherichia coli culture medium was not affected. The mortality rates were 100%, 45.3%, 2.8%, and 0% for Galleria, Lucilia, Plodia, and Culex, respectively, in another control group given a culture medium of Photorhabdus luminescens ssp. laumondii (TT01). In addition, culture media containing Photorhabdus strains significantly inhibited molting of third instar Plodia larvae by as much as 88% 7days after treatment, whereas molting inhibition was reduced by 0%, 4%, and 20% following treatments with water, E. coli, or TT01 culture media, respectively. Our results suggest that the oral administration of Photorhabdus bacterial medium was highly effective for controlling various immature insects. [Copyright &y& Elsevier]

The article describes a study which evaluated the antibacterial and anticancer activities of organic extracts taken from six seaweeds collected from Todos Santos Bay, Mexico in order to contribute to the discovery of new drugs. The organic extracts were swabbed from bacteria-free algae and from surface-associated bacteria on which pathogen strains of Staphylococcus aureus, Klebsiella pneumoniae, Proteus mirabilis and Pseudomonas aeruginosa were used to test antibacterial activity and HCT-116 colon cancer cells for anticancer activity. It explains which pathogen strains showed anticancer activity and which extracts from the seaweed-associated bacteria inhibited the growth of the pathogen strain Proteus mirabilis.

In this study, we determined the concentrations of Cu, Zn, Ni, Cd, Pb and As and their subcellular distributions within the tissues of mussels (Bathymodiolus marisindicus) and snails (Gigantopelta aegis) from two hydrothermal vent regions, i.e., Tiancheng and Longqi, at Southwest Indian Ridge. Mussels collected from the two venting regions showed comparable concentrations for Ni and Pb, but Cu, Zn, Cd and As concentrations were significantly different in mussel gills between the two vent regions. Similar ranges of metal concentrations were found in the snails as those in the mussels, but most of the metals were mainly accumulated in the viscera, except for Ni. Similar subcellular partitioning of Cu, Zn and Cd was documented in different mussel tissues, with cellular debris (50%) being the predominant fraction, followed by equivalent values in other fractions. Lead was distributed in both cellular debris and metal-rich granules (MRG) fraction, whereas Ni was predominantly distributed in MRG (90%). Arsenic was mainly partitioned in cellular debris and metallothionein-like protein. However, deep-sea snails displayed elevated subcellular partitioning of Cu in the organelles (up to 60%) and may be more susceptible to Cu stress than the mussels. Our results demonstrated the metal-specificity of detoxification strategies in these deep-sea hydrothermal vent mollusks, and the mussels may be more adaptable to high metal exposures than the snails at hydrothermal vent. Image 1 • Site-to-site variation of Cu and Zn concentrations within mussel tissues at Southwest Indian Ridge. • Cellular debris was the major fraction for Cu, Zn and Cd storage in mussels while Ni was mainly distributed in MRG. • Arsenic was evenly distributed in cellular debris and metallothionein-like protein in these two mollusks. • Snail oesophageal gland presented excessive Cu and Zn distributions in metal sensitive fraction. • Deep-sea mussels had greater capacity to detoxify metals at hydrothermal vent than snails. [ABSTRACT FROM AUTHOR]

Bacteria belonging to the Lachnospiraceae family are abundant, obligate anaerobic members of the microbiota in healthy humans. Lachnospiraceae impact their hosts by producing short-chain fatty acids, converting primary to secondary bile acids, and facilitating colonization resistance against intestinal pathogens. To increase our understanding of genomic and functional diversity between members of this family, we cultured 273 Lachnospiraceae isolates representing 11 genera and 27 species from human donors and performed whole-genome sequencing assembly and annotation. This analysis revealed substantial inter- and intra-species diversity in pathways that likely influence an isolate's ability to impact host health. These differences are likely to impact colonization resistance through lantibiotic expression or intestinal acidification, influence host mucosal immune cells and enterocytes via butyrate production, or contribute to synergism within a consortium by heterogenous polysaccharide metabolism. Identification of these specific functions could facilitate development of probiotic bacterial consortia that drive and/or restore in vivo microbiome functions. • Characterization of 273 human-derived Lachnospiraceae isolates • There is significant inter- and intra-species genomic diversity • Strain level differences may influence the development of therapeutic consortia Members of the Lachnospiraceae family are abundant members of the microbiota and have health-promoting functions. Sorbara et al. describe genomic and functional diversity within a large collection of cultured Lachnospiraceae isolates. Inter- and intra-species diversity has important implications for the development of therapeutic consortia. [ABSTRACT FROM AUTHOR]

Recently, there has been a growing interest in bacterial diversity in the phycosphere of microalgae because plant growth promoting bacteria (PGPB) increase algal biomass. However, the phycosphere bacterial community associated with the unicellular microalgae, Haematococcus strains, has not been studied to date, despite the broad industrial applications of these microalgae. Accordingly, in this study, we analyzed the characteristics of phycosphere bacterial communities associated with microalgae. The phycosphere bacterial community structure was dramatically shifted with each growth stage of Haematococcus lacustris. A symbiotic bacterium, Achromobacter sp. CBA4603, was identified and isolated from the Haematococcus culture and was found to produce high levels of auxin compared with other PGPB strains. During co-cultivation of Haematococcus pluvialis , which has high commercial value, with the isolated strain CBA4603, the growth of the microalga was enhanced at all growth stages, and the exponential stage was prolonged. However, the accumulation of astaxanthin was not high, which could be explained by the previously reported characteristics of exogenous auxin. Taken together, our results suggested that this Achromobacter strain may be useful for industrial and biotechnological applications to enhance biomass and for generation of high value-added products of H. pluvialis. • Our study first identified phycosphere bacterial community of a Haematococcus member. • We isolated the plant growth promoting bacteria (PGPB), Achromobacter sp. CBA4603 from a Haematococcus strain. • Achromobacter sp. CBA4603 produced indole-3-acetic acid (IAA) in quantities 20–390 times higher than other PGPB strains. • Achromobacter sp. CBA4603 promoted cell growth of Haematococcus strain. [ABSTRACT FROM AUTHOR]