Synthetic dyes, extensively used in various industries, act as pollutants in the aquatic environment, and pose a significant threat to living beings. In the present study, we assessed the potential ...of a halophilic bacterium
HTSP isolated from a saltpan for decolorization and bioremediation of synthetic dyes. The genomic assessment of this strain revealed the presence of genes encoding the enzymes involved in decolorization mechanisms including FMN-dependent NADH azoreductase Clade III, which cleave the azo bond of the dye, and the enzymes involved in deamination and isomerization of intermediate compounds. The dye decolorization assay was performed using this bacterial strain on three water-soluble dyes in different concentrations: Coomassie brilliant blue (CBB) G-250 (500-3,000 mg/L), Safranin, and Congo red (50-800 mg/L). Within 48 h, more than 80% of decolorization was observed in all tested concentrations of CBB G-250 and Congo red dyes. The rate of decolorization was the highest for Congo red followed by CBB G-250 and then Safranin. Using UV-Visible spectrometer and Fourier Transform Infrared (FTIR) analysis, peaks were observed in the colored and decolorized solutions. The results indicated a breakdown of dyes upon decolorization, as some peaks were shifted and lost for different vibrations of aromatic rings, aliphatic groups (-CH
, -CH
) and functional groups (-NH, -SO
H, and -SO
) in decolorized solutions. This study has shown the potential of
HTSP to decolorize dyes in higher concentrations at a faster pace than previously reported bacterial strains. Thus, we propose that our isolated strain can be utilized as a potential dye decolorizer and biodegradative for wastewater treatment.
The fatty acid composition of bacterial isolates remains stable under standardized culture conditions, which makes it a useful taxonomic marker. The present study aims to characterize the diversity ...and quantity of fatty acid methyl esters (FAME) profiles of cultivable bacterial isolates collected along the southwest coast of India. Based on the similarity indices (range > 0.3–0.7) of the FAME profiles, the isolates were aggregated into 10 families, 11 genera and 19 species of cultured isolates. The following classes of bacteria were found: Bacilli, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Actinobacteria, which also included a few pathogens such as
Pseudomonas
,
Staphylococcus
and
Bacillus
sp. The hydroxyl FAMEs 2-hydroxydodecanoic acid (C
12:0
2OH), 2-hydroxypentadecanoic acid (C
15:0
2OH),3-hydroxy 14-methylpentadecanoic acid (C
16:0
iso 3OH), 3 hydroxy hexadecenoic acid (C
16:0
3OH) and 3-hydroxy 15-methylhexadecanoic acid (C
17:0
iso 3OH), as well as the unsaturated FAMEs (11Z)-11-hexadecenoic acid (C
16:1
ɷ5c), were exclusively associated with the isolates from Mangalore samples. Similarly, FAMEs 2-hydroxydecanoic acid (C
10:0
2OH), 9-methyldecanoic acid (C
11:0
iso), undecanoic acid (C
11:0
), tridecanoic acid (C
13:0
), 10-methylhexadecanoic acid (C
16:0
10-CH
3
) and (7Z)-7-hexadecenoic acid (C
16:1
ɷ9c) occurred only in the isolates from Trivandrum samples. However, the isolates from Goa did not possess a signature FAME profile. The reproducibility of the GC-MIDI bacterial identification system was evaluated using 16S rRNA gene sequencing techniques for selected isolates.
Multidrug-resistant strains (MDRs) are becoming a major concern in a variety of settings, including water treatment and the medical industry. Well-dispersed catalysts such as BiPO4, ZnO nanoparticles ...(NPs), and different ratios of BiPO4/ZnO nanocomposites (NCs) were synthesized through hydrothermal treatments. The morphological behavior of the prepared catalysts was characterized using XRD, Raman spectra, PL, UV–Vis diffuse reflectance spectroscopy (UV-DRS), SEM, EDX, and Fe-SEM. MDRs were isolated and identified by the 16s rDNA technique as belonging to B. flexus, B. filamentosus, P. stutzeri, and A. baumannii. The antibacterial activity against MDRs and the photocatalytic methylene blue (MB) dye degradation activity of the synthesized NPs and NCs were studied. The results demonstrate that the prepared BiPO4/ZnO-NCs (B1Z4-75:300; NCs-4) caused a maximum growth inhibition of 20 mm against A. baumannii and a minimum growth inhibition of 12 mm against B. filamentosus at 80 μg mL−1 concentrations of the NPs and NCs. Thus, NCs-4 might be a suitable alternative to further explore and develop as an antibacterial agent. The obtained results statistically justified the data (p ≤ 0.05) via one-way analysis of variance (ANOVA). According to the results of the antibacterial and photocatalytic study, we selected the best bimetallic NCs-4 for the photoexcited antibacterial effect of MDRs, including Gram ve+ and Gram ve− strains, via UV light irradiation. The flower-like NCs-4 composites showed more effectiveness than those of BiPO4, ZnO, and other ratios of NCs. The results encourage the development of flower-like NCs-4 to enhance the photocatalytic antibacterial technique for water purification.
Elevated carbon dioxide levels in ocean waters, an anthropogenic stressor, can alter the chemical equilibrium of seawater through a process called ocean acidification (OA). The resultant reduction of ...pH can be detrimental during the early developmental stages of the commercially important edible Pacific oyster
Crassostrea gigas
; the ability of larvae to join a population is likely to be compromised by declining ocean pH. Given this threat, it is important to study the molecular mechanisms that these organisms use to overcome OA stress at the gene expression level. Here, we performed transcriptome profiling in oyster larvae following exposure to ambient (8.1) and reduced (7.4) pH during the pre-settlement growth period (i.e., 18 d post fertilization) using RNA-seq with Illumina sequencing technology. In total, 1,808 differentially expressed genes (DEGs) were identified, 1,410 of which were matched by BLAST against the Swiss-Prot database. Gene ontology classification showed that most of these DEGs were related to ribosomal, calcium ion binding, cell adhesion and apoptotic processes. Pathway enrichment analysis revealed that low pH (7.4) enhanced energy production and organelle biogenesis but prominently suppressed several immune response pathways. Moreover, activation of the MAPK signaling pathway was observed along with inhibition of the Wnt, VEGF, and ErbB pathways, highlighting the fact that the initiation of stress responses is given priority over larval development or shell growth when the larvae cope with low pH. In conclusion, our study demonstrated a unique gene expression profiling approach in studying oyster larval responses to OA, which not only provides comprehensive insights into the mechanisms underlying oyster tolerance to CO
2
-driven decreases in ocean pH but also supplies a valuable genomic resource for further studies in this species.
Fisheries and aquaculture have emerged as a promising food production sector at the global level as well as regional levels. Fish and fish products are produced in one region and then are traded ...across various parts of the world. The whole sector is dependent on chains of workers engaged at landing centres, breeding units, processing units, and the trade and export chains. When the pandemic and the subsequent lockdown hit the country, it affected the whole sector and caused a huge decline in the production and trade of fishing products. This article aims to have a glimpse into the aquaculture sector and evaluate the impact of the pandemic on this sector in India. This valuable information can be of great importance to government and aquatic food suppliers so that they can evolve their strategies to withstand ongoing and future pandemics. It also helps them in framing regional and sectorial adjustments to transform investment plans, match market demands, improve monitoring strategies and get prepared for future needs.
•The purpose of this article is to have a glimpse into the aquaculture sector and evaluate the impact of the COVID-19 pandemic on this sector in India.•This valuable information can be of great importance to the government and aquatic food suppliers so that they can evolve their strategies to withstand ongoing and future pandemics.•It also helps them frame regional and sectorial adjustments to transform investment plans, match market demands, improve monitoring strategies and prepare for future needs.•Some of the major challenges the entire fishing community faced during the COVID-19 lockdown are (i)difficulty in hiring truck drivers for transport of cargo.•(ii) Delayed seaweed seed material transportation.•(iii) Total shutdown of shrimp processing unit, forced engagement of minimal labour in shrimp feed, medicine and probiotics industries.•and (iv) Negative impacts on the livelihood of local fishermen due to fishing ban and low demand.•The paper also summarizes the reformations in the aquaculture sector in India to future pandemics.•Outbreak of COVID-19 has stimulated digital transformation across many aquaculture supply chain in India to reduce the dependence on manpower.•Scientific farming practices, the inclusion of technology and decreasing the over-dependency on export (around 90%) can recover the sector and can help take it to a desired level.
The metamorphosis of planktonic larvae of the Pacific oyster (Crassostrea gigas) underpins their complex life‐history strategy by switching on the molecular machinery required for sessile life and ...building calcite shells. Metamorphosis becomes a survival bottleneck, which will be pressured by different anthropogenically induced climate change‐related variables. Therefore, it is important to understand how metamorphosing larvae interact with emerging climate change stressors. To predict how larvae might be affected in a future ocean, we examined changes in the proteome of metamorphosing larvae under multiple stressors: decreased pH (pH 7.4), increased temperature (30 °C), and reduced salinity (15 psu). Quantitative protein expression profiling using iTRAQ‐LC‐MS/MS identified more than 1300 proteins. Decreased pH had a negative effect on metamorphosis by down‐regulating several proteins involved in energy production, metabolism, and protein synthesis. However, warming switched on these down‐regulated pathways at pH 7.4. Under multiple stressors, cell signaling, energy production, growth, and developmental pathways were up‐regulated, although metamorphosis was still reduced. Despite the lack of lethal effects, significant physiological responses to both individual and interacting climate change related stressors were observed at proteome level. The metamorphosing larvae of the C. gigas population in the Yellow Sea appear to have adequate phenotypic plasticity at the proteome level to survive in future coastal oceans, but with developmental and physiological costs.
Multidrug-resistant strains (MDRs) are becoming a major concern in a variety of settings, including water treatment and the medical industry. Well-dispersed catalysts such as BiPO
, ZnO nanoparticles ...(NPs), and different ratios of BiPO
/ZnO nanocomposites (NCs) were synthesized through hydrothermal treatments. The morphological behavior of the prepared catalysts was characterized using XRD, Raman spectra, PL, UV-Vis diffuse reflectance spectroscopy (UV-DRS), SEM, EDX, and Fe-SEM. MDRs were isolated and identified by the 16s rDNA technique as belonging to
,
,
, and
. The antibacterial activity against MDRs and the photocatalytic methylene blue (MB) dye degradation activity of the synthesized NPs and NCs were studied. The results demonstrate that the prepared BiPO
/ZnO-NCs (B1Z4-75:300; NCs-4) caused a maximum growth inhibition of 20 mm against
and a minimum growth inhibition of 12 mm against
at 80 μg mL
concentrations of the NPs and NCs. Thus, NCs-4 might be a suitable alternative to further explore and develop as an antibacterial agent. The obtained results statistically justified the data (
≤ 0.05) via one-way analysis of variance (ANOVA). According to the results of the antibacterial and photocatalytic study, we selected the best bimetallic NCs-4 for the photoexcited antibacterial effect of MDRs, including Gram ve
and Gram ve
strains, via UV light irradiation. The flower-like NCs-4 composites showed more effectiveness than those of BiPO
, ZnO, and other ratios of NCs. The results encourage the development of flower-like NCs-4 to enhance the photocatalytic antibacterial technique for water purification.
PDF
