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Di-n-butyl phthalate (DBP) is a prevalent phthalate ester widely used as a plasticizer, leading to its widespread presence in various environmental matrices. This study presents an innovative microbial immobilization strategy utilizing biochar, calcium alginate (alginate-Ca, (C12H14CaO12)n), and waterborne polyurethane (WPU) composites to enhance the biodegradation efficiency of DBP. The results revealed that rice husk biochar, pyrolyzed at 300 °C, exhibits relatively safer and more stable physical and chemical properties, making it an effective immobilization matrix. Additionally, the optimal cultural conditions for Bacillus aquimaris in DBP biodegradation were identified as incubation at 30 °C and pH 7, with the supplementation of 0.15 g of yeast extract, 0.0625 g of glucose, and 1 CMC of Triton X-100. Algal biotoxicity results indicated a significant decrease in biotoxicity, as evidenced by an increase in chlorophyll a content in Chlorella vulgaris following DBP removal from the culture medium. Finally, microbial community analysis demonstrated that encapsulating B. aquimaris within alginate-Ca and WPU layers not only enhanced DBP degradation, but also prevented ecological competition from indigenous microorganisms. This novel approach showcases the potential of agricultural waste utilization and microbial immobilization techniques for the remediation of DBP-contaminated environments. [ABSTRACT FROM AUTHOR]

Di-n-butyl phthalate (DBP) is a prevalent phthalate ester widely used as a plasticizer, leading to its widespread presence in various environmental matrices. This study presents an innovative microbial immobilization strategy utilizing biochar, calcium alginate (alginate-Ca, (C12H14CaO12)n), and waterborne polyurethane (WPU) composites to enhance the biodegradation efficiency of DBP. The results revealed that rice husk biochar, pyrolyzed at 300 °C, exhibits relatively safer and more stable physical and chemical properties, making it an effective immobilization matrix. Additionally, the optimal cultural conditions for Bacillus aquimaris in DBP biodegradation were identified as incubation at 30 °C and pH 7, with the supplementation of 0.15 g of yeast extract, 0.0625 g of glucose, and 1 CMC of Triton X-100. Algal biotoxicity results indicated a significant decrease in biotoxicity, as evidenced by an increase in chlorophyll a content in Chlorella vulgaris following DBP removal from the culture medium. Finally, microbial community analysis demonstrated that encapsulating B. aquimaris within alginate-Ca and WPU layers not only enhanced DBP degradation, but also prevented ecological competition from indigenous microorganisms. This novel approach showcases the potential of agricultural waste utilization and microbial immobilization techniques for the remediation of DBP-contaminated environments.

This field study was performed to demonstrate that Bacillus aquimaris SH6 spores administered as a feed supplement in adequate amounts confer beneficial effects to the whiteleg shrimp. Shrimps were administered either B. aquimaris SH6 spores at 1×106 CFU g-1 pellet (SH6 group) or a mixture of SH6 and B. subtilis SH23 spores at 5×105 CFU g-1 pellet for each strain (SH6-SH23 group). After a 28-day feeding period, the number of SH6 spores in the gut of whiteleg shrimp in the SH6 group and the SH6-SH23 group were 5.7×103 CFU gut-1 and 7.7×103 CFU gut-1, respectively. The total bacterial population of these two experimental groups increased about 10-75% compared to that of the control group. The astaxanthin level and red colour score were the highest in the SH6-SH23 group (1.66 µg.g-1 shrimp; 28-29), followed by the SH6 spore group (1.42 µg.g-1 shrimp; 27-28), and were the lowest in the control group (0.61 µg.g-1 shrimp; 26-27). Nevertheless, the growth rate of shrimps was similar (7.8-8%) among the three groups. In conclusion, feed supplements containing SH6 and SH23 spores co-effectively improved live counts and diversity of microbiota in shrimp guts, as well as improved astaxanthin level and red colour of whiteleg shrimps.

Modern biotechnology takes into account cost, performance, and respect for the environment to set up an industrial process. In this sense, the study's goal is to highlight the presence of indigenous microbial microflora in the Terga thermal power plant effluents, which are capable of secreting extracellular hydrolases. Four different extracellular hydrolases classes, which are most of the time used in bioindustry, namely protease, amylase, lipase, and cellulase, were investigated in agar plate assay, to select microorganisms with an interesting enzymatic potential adapted to this type of environment. Consequently, the results have shown that among twelve isolated bacterial strains, three strains were screened based on their enzymatic potential, and were later identified by 16S rRNA gene sequencing, i.e. showing that the strains belong to the genus Pseudomonas aeruginosa, and Bacillus wiedmannii with a similarity percentage of 99.33% and 100%, respectively, with their corresponding type of strains. Among them, the strain LGMT10 that belongs to the Bacillus genus, and is closely related to Bacillus aquimaris, showed a 16S rRNA sequence similarity with the type of strain of 99.23%. This strain presents adequate characteristics to resist the harsh conditions of pH and NaCl. It could grow against wide ranges of NaCl concentrations between 0-12% (w/v), pH 5.5-12, and was able to produce extracellular hydrolases (i.e., protease, amylase, and cellulase) against pH ranges of 6.8-12 and NaCl concentrations between 0-12% (w/v) at 30 °C. This strain's intriguing enzymatic potential, as well as its pH and salinity tolerance, make it a promising candidate for various biotechnological applications in detergent, leather, textile, and food processing industries. [ABSTRACT FROM AUTHOR]

A 49‐day rearing trial was conducted to investigate the effects of Bacillus aquimaris T16 on growth, survival, and digestive and immune‐related enzyme activities in larval and juvenile Yesso scallop, Patinopecten yessoensis. Veliger larvae (Day 2 postfertilization [d2 PF]) were split into three treatments: control (provided with a diet only of microalgae), low T16 supplementation (1 × 104 cells/mL at final concentration), and high T16 supplementation (1 × 106 cells/mL at final concentration). Results showed that specific growth rates; survivals; and pepsin, amylase, and/or cellulase activities of umbo larvae (d13 PF), crawling–pediveliger larvae (d28 PF), and juveniles (d51 PF) in the low and/or high T16 supplementation treatments were significantly higher than those in the control group. Larvae and juveniles fed diets containing low and/or high T16 supplementations had significantly increased lysozyme, superoxide dismutase, and catalase activities compared with those fed the diet of microalgae. In addition, T16 protected juveniles against challenge by Vibrio splendidus. These data suggest that the addition of T16 can improve growth, enhance digestive enzyme activity, and stimulate the innate immune system of scallop larvae and juveniles and enhance the resistance of juveniles against V. splendidus. [ABSTRACT FROM AUTHOR]

Aim: Di-(2-ethylhexyl) phthalate (DEHP) has been identified as an endocrine-disrupting chemical, commonly found in the environment. The aim of this study was to isolate bacteria from municipal solid waste (MSW) leachates in Nigeria and its ability to degrade DEHP. Methodology and results: The DEHP degrading bacterium was isolated and identified. The degradation process was monitored aerobically at varying temperature and pH and the metabolites were determined using High Performance- Liquid Chromatography and Gas Chromatography-Mass Spectrometry, respectively. Based on the morphology and the 16S rDNA sequence, the bacterial isolate was identified as Bacillus aquimaris. B aquimaris was able to degrade 99% of 200 mg/L DEHP within 12 days. The optimum pH and temperature for its biodegradation were 8 and 25 °C, respectively and the intermediate metabolites were identified as butyl octyl phthalate and phthalic acid. Conclusion, significance and impact of study: This study showed that B. aquimaris could be a useful tool for the biodegradation of DEHP in the environment. [ABSTRACT FROM AUTHOR]

Our objective was to evaluate the role of plant growth-promoting bacteria to protect maize ( Zea mays L.) plants against salt damage. Bacillus aquimaris DY-3 based on their 16S rDNA sequences, the most tolerant to salinity and the synthesis of indole acetic acid was selected for further studies. Strain was inoculated on maize roots growing in sterilized sand under salt stress conditions (1% NaCl). After one week, plant growth was promoted by bacterial inoculation regardless of salt stress and non-salt stress. Chlorophyll content, leaf relative water content, accumulation of proline, soluble sugar and total phenolic compound, and activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase were enhanced, while lipid peroxidation levels and Na content were decreased. The results showed that B. aquimaris DY-3 alleviated the salt stress in maize, likely through the integration of the antioxidant enzymes and the non-antioxidant systems that improve the plant response. Hence, the application of indole acetic acid synthesizing plant growth-promoting bacteria may represent an important alternative approach to decrease the impact of salt stress on crops. [ABSTRACT FROM AUTHOR]

Background: The unique ecosystem of the Persian Gulf has made it a rich source of natural antimicrobial compounds produced by various microorganisms, especially bacteria, which can be used in the treatment of infectious diseases, especially those of drug-resistant microbes., Objectives: This study aimed to identify antimicrobial compounds in the bacteria isolated from the northern region of the Persian Gulf in Abadan (Chavibdeh port), Iran, for the first time., Materials and Methods: Sampling was performed in the fall on November 15, 2019, from 10 different stations (water and sediment samples). The secondary metabolites of all isolates were extracted, and their antimicrobial effects were investigated. 16S ribosomal ribonucleic acid sequencing was used for the identification of the strains that showed the best inhibition against selected pathogens, and growth conditions were optimized for them. A fermentation medium in a volume of 5000 mL was prepared to produce the antimicrobial compound by the superior strain. The extracted antimicrobial compounds were identified using the gas chromatography-mass spectrometry technique. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for the superior strain. The effects of salinity, pH, and temperature on the production of antimicrobial compounds were determined by measuring the inhibitory region (mm) of methicillin-resistant Staphylococcus aureus (MRSA)., Results: Four new strains with antimicrobial properties (i.e., Halomonas sp. strain Persiangulf TA1, Bacillus aquimaris strain Persiangulf TA2, Salinicoccus roseus strain Persiangulf TA4, and Exiguobacterium profundum strain Persiangulf TA9) were identified. The optimum growth temperatures were determined at 37-30, 37, and 40 °C for TA1 and TA2, TA4, and TA9 strains, respectively. The optimum pH values for the four strains were 7, 6-7, 7.5, and 6.5-7.5, respectively. The optimal salt concentrations for the four strains were 15%, 2.5-5%, 7.5%, and 5%, respectively. The ethyl acetate extract of strain Persiangulf TA2 showed extensive antimicrobial activity against human pathogens (75%) and MRSA. The most abundant compound identified in TA2 extract was the new compound 4-fluoro-2-trifluoromethyl imidazole. The MBC and MIC for the ethyl acetate extract of strain TA2 were 20 and 5 mg. mL -1 ( Staphylococcus aureus ), 40 and 20 mg. mL -1 (MRSA, Escherichia coli , and Enterococcus faecalis ), 40 and 10 mg. mL -1 Acinetobacter baumannii ), and 80 and 40 mg. mL -1 ( Staphylococcus epidermidis , Shigella sp., Bacillus cereus , and Klebsiella pneumoniae ), respectively. The optimal conditions for antibiotic production by TA2 strain were 5% salt concentration, pH of 7, and temperature of 35 °C., Conclusion: Newly detected natural compounds in TA2 strain due to superior antimicrobial activity even against MRSA strain can be clinically valuable in pharmacy and treatment., Competing Interests: Sara Taghavi, Effat Abbasi Montazeri, Roya Zekavati, laleh Roomiani and Parvaneh Saffarian declare that they have no conflict of interest., (Copyright: © 2021 The Author(s); Published by Iranian Journal of Biotechnology.)

Heavy metals present in the environment posses significant global problem and warrant ultimate remediation measurement. In the present study, bacteria were isolated from the Yangtze River, China and six isolates were further selected on the basis of tolerance to various heavy metals. Based on various biochemical, physiological and 16S rDNA analyses; these bacteria belonged to five distinct genera, Pseudomonas putida, Cupriavidus necator, Exiguobacterium sp., Bacillus aquimaris, B. cereus, and Alcaligenes sp. Minimum inhibitory concentration test recorded that Pseudomonas putida YR8 andAlcaligenes sp. YR11 had a high level of tolerance (between 5 and 10 mM) to the heavy metals tested. The multiple heavy-metal resistant bacteria of present study could survive well in the heavy metal contaminated environment and thus can be exploited for the remediation of metals from such environment. © 2014 Friends Science Publishers [ABSTRACT FROM AUTHOR]

Abstract: The organic solvent tolerant bacteria with their physiological abilities to decontaminate the organic pollutants have potentials to secrete extracellular enzymes of commercial importance. Of the 19 marine bacterial isolates examined for their solvent tolerance at 10vol.% concentration, one had the significant tolerance and showed a relative growth yield of 86% for acetone, 71% for methanol, 52% for benzene, 35% for heptane, 24% for toluene and 19% for ethylacetate. The phylogenetic analysis of this strain using 16S rDNA sequence revealed 99% homology with Bacillus aquimaris. The cellulase enzyme secreted by this strain under normal conditions showed an optimum activity at pH 11 and 45°C. The enzyme did show functional stability even at higher pH (12) and temperature (75°C) with residual activity of 85% and 95% respectively. The enzyme activity in the presence of different additives were in the following order: Co+2 >Fe+2 >NaOCl2 >CuSO4 >KCl>NaCl. The enzyme stability in the presence of solvents at 20vol.% concentration was highest in benzene with 122% followed by methanol (85%), acetone (75%), toluene (73%) and heptane (42%). The pre-incubation of enzyme in ionic liquids such as 1-ethyl-3-methylimidazolium methanesulfonate and 1-ethyl-3-methylimidazolium bromide increased its activity to 150% and 155% respectively. The change in fatty acid profile with different solvents further elucidated the physiological adaptations of the strain to tolerate such extreme conditions. [Copyright &y& Elsevier]

Abstract: A newly isolated halotolerant Bacillus sp. VITP4 was investigated for the production of extracellular protease. 16S rRNA gene analysis identified it as Bacillus aquimaris. Enzyme secretion corresponded with growth (G t , 38min) in the basal Zobell medium, reaching a maximum during stationary phase (630U/ml, 48h). Protease production was investigated in different salt concentrations (0–4M). While growth was optimum in the basal medium, higher levels of protease activity were observed in 0.5M salt medium (728U/ml, 48h) and 1M salt medium (796U/ml, 78h) with 21% and 32% increase in production, respectively. Salt concentrations above 2.5M did not support bacterial growth. The optimum pH and temperature for production were pH 7.5 and 37°C, respectively. A combination of peptone and yeast extract yielded optimum protease secretion. Inorganic nitrogen sources proved to be less favourable. Production was reduced in the presence of readily available carbon sources owing to catabolic repression. Effect of various salts (1–6%) indicated favourable bacterial growth in these conditions for producing proteolytic molecules with increased activity. The study assumes significance in the ability of the halotolerant bacterium to survive in a wide range of salinity and yield optimum levels of extracellular protease. [Copyright &y& Elsevier]