Strain A1 Research Articles

Defluorination of various perfluoro alkyl acids and selected PFOA and PFOS monomers by Acidimicrobium sp. Strain A6 enrichment cultures

Per- and polyfluoroalkyl substances (PFAS) have emerged as a diverse class of environmental pollutants, garnering increasing attention due to their various structural types and potential ecological impacts. The impact of select PFAS on environmental microorganisms and the potential for microbial degradation of certain PFAS are timely research topics. In this study, we conducted a series of batch incubation to investigate the effects of C4-C10 perfluoroalkyl carboxylic acids (PFCAs) and perfluorosulfonic acids (PFSAs), as well as linear and branched perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) monomers, on the Feammox reaction and Acidimicrobium sp. A6 (A6), a microbe known to degrade PFOA and PFOS. We explored the defluorination ability of A6 cultures with these PFAS, evaluating their response to varying chemical structures. While A6 cultures demonstrated the ability to degrade a wide range of PFAAs (11.5–56.9 % reduction over 120 days), challenges were noted with specific compounds like PFPeA and double-branched PFCAs and PFSAs, which also showed reduced ammonium removal. Additionally, exposure to the selected PFAS resulted in notable shifts in the microbial community within the A6 enrichment cultures, indicating a selective pressure that benefits certain strains (e.g., increased percentages of Acidimicrobium, Paraburkholderia, and Desulfosporosinus in several PFCA, PFSA and PFOA/PFOS monomers enriched cultures). These insights contribute to our understanding of microbial-PFAS interactions and are instrumental in developing bioremediation strategies for PFAS-impacted environments.

Comparative study of endophytic bacterial strains from non-host crops for enhancing plant growth and managing early blight in tomato.

Bacillus pseudomycoides, Paenibacillus polymyxa, and B. velezensis are potent bacterial endophytes, which typically exhibit host-specific interactions. However, comparative studies of these endophytes in vitro and in planta in non-host crops are lacking. Therefore, in this study, we evaluated the potential of endophytes B. pseudomycoides strain HP3d, P. polymyxa strain PGSS1, B. velezensis strain A6, and P42, isolated from various crop ecosystems in promoting plant growth and inducing systemic resistance against early blight disease in tomato. In vitro, endophytes exhibited 44.44-55.56% and 37.50-87.50% inhibition of Alternaria solani in dual culture and volatilome bioassay, respectively. In the glasshouse, individual and combined applications via seed treatment (ST), seedling dip (SD), and foliar spray (FS) significantly enhanced shoot growth (23.63-57.61%), root growth (43.27-118.23%), number of leaves (77.52-93.58%), number of shoots (33.42-45.28%) and root dry matter (42.17-43.86%), reducing early blight (PDI) by 70.95-76.12% compared to uninoculated control. Enzymatic activities, including such as polyphenol oxidase (30-40 fold), peroxidase (65.00-75.00 fold), superoxide dismutase (34.20-37.20 fold) and phenylalanine ammonia-lyase (44.44-45.56 fold) were elevated post-inoculation in endophytes treated tomato plants challenged with A. solani compared to control treated only with A. solani and declined after the fifth day. The total chlorophyll content declined from the 0th to the 10th day, but endophyte treated plants exhibited lesser reductions (2.03-2.09) than uninoculated control. Field trials confirmed the glasshouse findings, showing reduced early blight and improved growth parameters in tomato where the ST + SD + FS combination emerged as the most effective treatment for all endophytes showing 1.06-1.88 fold increase in fruit yield per plant and 28.92-32.52% decrease in PDI compared to untreated control. Thus, the study highlights the broad-spectrum potential of these strains in promoting plant growth and controlling early blight in tomato, demonstrating non-host specificity. These endophytes offer eco-friendly alternatives to chemical pesticides, supporting sustainable agriculture. Their success in field trials suggests the potential for commercialization and large-scale use across diverse crops and pave the way for further interdisciplinary research to optimize their application in integrated pest management strategies.

Stimulating Acidimicrobium sp. Strain A6 in iron-rich, acidic sediments from AFFF-impacted sites for PFAS defluorination

Per- and polyfluoroalkyl substances (PFAS) are persistent and bioaccumulative contaminants that are widely used in industrial applications and consumer products and pose significant risks to ecosystems and human health. Acidimicrobium sp. Strain A6 (A6), which is common in acidic, and iron rich soils and sediments is capable of both anaerobic ammonium (NH4+) oxidation under iron reduction (Feammox) and defluorination of perfluorinated alkyl substances, such as perfluoroalkyl acids (PFAAs). This study investigates the potential for biostimulating A6 via the supply of NH4+ and ferric iron (Fe(III)) with the goal of defluorinating PFAAs. Sediment samples from acidic, iron-rich, AFFF (aqueous film forming foam) impacted sites were collected and incubated with added Fe(III) and NH4+. Quantitative PCR was used to track A6 numbers as well as dehalogenase and F− ion transporter genes during these incubations; changes in the microbial community structure were tracked through 16S rRNA gene sequencing. The findings reveal that the addition of Fe(III) and NH4+ stimulated the Feammox reaction and A6 growth and enhanced the degradation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). Results also show a significant presence and activity of the above-mentioned genes in these incubations. The insights gained from this study could inform bioremediation strategies for PFAS-contaminated environments, especially in geochemical settings that favor the presence of A6.

Deciphering the defense response in tomato against Sclerotium rolfsii by Trichoderma asperellum strain A10 through gene expression analysis.

The online version contains supplementary material available at 10.1007/s13205-024-04040-4.

Annotation-Based Study on Hypothetical Proteins in Bacteria Using Classification Features

Background: Hypothetical proteins (HPs) are those proteins whose functions are unknown; therefore, the present study was carried out to predict similarity-based functionality of HPs in selected bacteria Streptomyces coelicolor A3(2) and Neisseria meningitidis. Methods: Annotation-based approaches using Pfam, orthology, String, Bi-directional Best Blast Hit, PSLpred, Subloc, Cello, homology modeling, and computational tools were used in evaluating the functionality of HPs. Results: Thirty-one domains in both bacterial species were retrieved based on the E-value score and compared with bacterial species already existing in databases. Statistical analysis was duly done to check which features performed well Conclusion: Out of 31 HPs found in Streptomyces coleicolor strain A3(2), 14 domains were found to be uncharacterized in their functionality, while 2 uncharacterized domains in the case of Neisseria meningitidis were assigned a function on similarity-based approaches. The annotation of HPs is a challenge in bacteria as these are based on the similarity of proteins in other species.

Evaluating the Potential of Bacillus Isolates for Chlorpyrifos Degradation and Their Role in Tea Growth Promotion and Suppression of Pathogens.

Pesticides employed for controlling domestic and agricultural pests are among the most dangerous environmental contaminants. Nevertheless, negligent usage and a lack of technical expertise have led to the contamination and pollution of various ecological niches. The extensive utilization of the organophosphate chlorpyrifos (CPs) for insect infestation control, coupled with its detrimental effects and persistence in the ecosystem, has led to calls for its removal from contaminated sites. The study is mainly focused on degradation of CPs; using viz. Bacillus wiedmannii A3 and Bacillus cereus P14 isolated from tea rhizosphere soil having pesticide contamination in Sonitpur district, Assam, India. These two bacterial strains were able to degrade CPs in vitro within 3days. Reverse-phase HPLC analysis suggested about 96% reduction of CPs concentration upon bacterial treatment. Again, in case of A3, GC-MS analysis revealed that CPs was modified to 2-hydroxy-3,5,6-trichloropyridine and chlorpyrifos-oxon, thus finally metabolized into non-toxic products. While analyzing P14, silane, dimethyl (2,2,2-trichloroethoxy) propoxy, and 3-aminobenzoic acid, N-trimethylsilyl-, trimethylsilyl ester were identified. These compounds were subsequently transformed into non-toxic products. In addition to this, they demonstrated a significant boost of plant growth-promoting traits in both absence and presence of CPs; also showed growth development in nursery scale condition. Moreover, they functioned as biocontrol agents against Phellinus lamaensis and Colletotrichum gloeosporioides, responsible for brown root rot and anthracnose in North East India tea plantations, respectively. Thus, the pesticide-tolerant Bacilli strains A3 and P14 could be used as bioremediation of contaminated sites and also as biostimulants, and biocontrols in tea crop production.

Oral Administration of Probiotic Bifidobacterium breve Ameliorates Tonic-Clonic Seizure in a Pentylenetetrazole-Induced Kindling Mouse Model via Integrin-Linked Kinase Signaling.

Epilepsy is a chronic neurological disorder characterized by recurrent seizures that affects over 70 million people worldwide. Although many antiepileptic drugs that block seizures are available, they have little effect on preventing and curing epilepsy, and their side effects sometimes lead to serious morbidity. Therefore, prophylactic agents with anticonvulsant properties and no adverse effects need to be identified. Recent studies on probiotic administration have reported a variety of beneficial effects on the central nervous system via the microbiota-gut-brain axis. In this study, we investigated the effects of the oral administration of Bifidobacterium breve strain A1 [MCC1274] (B. breve A1) on tonic-clonic seizure in a pentylenetetrazole (PTZ)-induced kindling mouse (KD mouse) model. We found that the oral administration of B. breve A1 every other day for 15 days significantly reduced the seizure score, which gradually increased with repetitive injections of PTZ in KD mice. The administration of B. breve A1, but not saline, to KD mice significantly increased the level of Akt Ser473 phosphorylation (p-Akt) in the hippocampus; this increase was maintained for a minimum of 24 h after PTZ administration. Treatment of B. breve A1-administered KD mice with the selective inhibitor of integrin-linked kinase (ILK) Cpd22 significantly increased the seizure score and blocked the antiepileptic effect of B. breve A1. Moreover, Cpd22 blocked the B. breve A1-induced increase in hippocampal p-Akt levels. These results suggest that the ILK-induced phosphorylation of Akt Ser473 in the hippocampus might be involved in the antiepileptic effect of B. breve A1.

Evaluation of Probiotics Ability to Enhance Population Density, Growth Rate, and Neonates Production of Moina micrura in Different Environmental Parameters

Salinity, light intensity, and oxygen concentration are key environmental factors that significantly affect biological processes and the composition and dispersion of Moina biomass. Evaluating the effectiveness of probiotic enrichment in improving population density, growth rate, and neonate production can provide valuable details on the effectiveness of probiotics in enhancing the resilience and viability of Moina micrura under suboptimal circumstances. The purpose of this research project is to assess the efficacy of two probiotics, Bacillus pocheonensis strain S2 and Lysinibacillus fusiformis strain A1, in improving the population density, growth rate, and reproductive output in M. micrura across various environmental conditions. Moina micrura were treated with each probiotic at a volume of 5 x 105 CFU/ml under different levels of salinity (0, 2, 4, and 6 ppt), light intensity (800, 1,000, 1,500, and 2,000 lux), and oxygen concentration (80, 70, 60, and 50%). The results indicated that M. micrura treated with L. fusiformis A1 at 0 ppt attained the highest population density (6 ± 0.90 Ind./ml), growth rate (0.355 ± 0.030 µ), and number of offspring production (5 ± 0.75 Ind./ml). The highest point of population density (5 ± 0.07 Ind./ml), growth rate (0.381 ± 0.002 µ) and number of offspring (7 ± 0.41 Ind./ml) of M. micrura were obtained while treated with B. pocheonensis S2 at light intensity of 1,500 lux. Similarly, the highest population density (5 ± 0.60 Ind./ml), growth rate (0.365 ± 0.190 µ), and offspring production (2 ± 0.25 Ind./ml) of M. micrura were observed during enrichment with B. pocheonensis S2 at 70% oxygen concentration. Therefore, these results suggested that the optimum conditions for enriching M. micrura with B. pocheonensis S2 are salinity of 0 ppt, 70% oxygen concentration, and a light intensity level of 1,500 lux.

Actinobacteria Isolated from Soils of Arid Saharan Regions Display Simultaneous Antifungal and Plant Growth Promoting Activities.

Application of actinobacteria has grown exponentially in recent years in sustainable agricultural. Most actinobacterial inoculants are tailored to function as either biocontrol agents or biofertilizers. Hence, there is the need to obtain and include multifunctional actinobacterial strains in inocula formulations. In this research, 90 actinobacterial isolates were isolated from rhizospheric and non-rhizospheric soils of Algerian Saharan arid regions and were screened for their activity against the phytopathogenic fungi Alternaria alternata, Aspergillus flavus, Botrytis cinerea, Fusarium oxysporum, and Fusarium solani. Five isolates that inhibited at least three of these fungi were characterized according to morphological, environmental and biochemical parameters, and were preliminarily identified as Streptomyces enissocaesilis A1, Streptomyces olivoverticillatus A5, Streptomyces erumpens A6, Streptomyces cavourensis A8, and Streptomyces microflavus A20. These strains were then screened for plant growth promoting activities. All strains produced siderophores, hydrocyanic acid, ammonia and the auxin indole-3-acetic acid (IAA) and were capable of solubilizing phosphate. The highest producer of siderophores (69.19 percent siderophore units), ammonia (70.56μgmL-1) and IAA (148.76μgmL-1) was strain A8, A20, and A5, respectively. These findings showed that the five actinobacteria are multipurpose strains with simultaneous antifungal and plant growth promoting activities and have the potential to be used for sustainable agricultural practices, particularly in arid regions.

Effective enhancement of the ability of Monascus pilosus to produce lipid-lowering compound Monacolin K via perturbation of metabolic flux and histone acetylation modification

Monacolin K (MK), also known as lovastatin, is a polyketide compound with the ability to reduce plasma cholesterol levels and many other bio-activities. Red yeast rice (also named Hongqu) rich in MK derived from Monascus fermentation has attracted widespread attention due to its excellent performance in reducing blood lipids. However, industrial Monascus fermentation suffers from the limitations such as low yield of MK, long fermentation period, and susceptibility to contamination. In this study, we firstly blocked the competitive pathway of MK biosynthesis to create polyketide synthase gene pigA (the key gene responsible for the biosynthesis of Monascus azaphilone pigments) deficient strain A1. Then, based on the strategies to increase precursor supply for MK biosynthesis, acetyl-CoA carboxylase gene acc overexpression strains C1 and C2 were constructed with WT and A1 as the parent, respectively. Finally, histone deacetylase gene hos2 overexpression strain H1 was constructed by perturbation of histone acetylation modification. HPLC detection revealed all these four strains significantly increased their abilities to produce MK. After 14 days of solid-state fermentation, the MK yields of strains A1, C1, C2, and H1 reached 2.03 g/100 g, 1.81 g/100 g, 2.45 g/100 g and 2.52 g/100 g, which increased by 28.5 %, 14.7 %, 43.9 % and 36.1 % compared to WT, respectively. RT-qPCR results showed that overexpression of hos2 significantly increased the expression level of almost all genes responsible for MK biosynthesis after 5-day growth. Overall, the abilities of these strains to produce MK has been greatly improved, and MK production period has been shortened to 14 days from 20 days, providing new approaches for efficient production of Hongqu rich in MK.

Antitumor properties of traditional lactic acid bacteria: Short-chain fatty acid production and interleukin 12 induction

This paper presents an in vitro evaluation of antitumor properties through producing short-chain fatty acids and inducing interleukin 12. In addition, it offers the most important and functional probiotic properties of 24 Lactobacillus gasseri, Lactiplantibacillus plantarum, Lactobacillus acidophilus, and Limosilactobacillus fermentum strains isolated from humans, foods, and fermented foods. To this end, survival in an acidic environment (pH = 2.5), tolerance in bile salt, viability in the presence of pepsin-pancreatin, adhesion percentage, antibiotic resistance, auto-aggregation, and potential percentage of co-aggregation are studied in contact with three human intestinal pathogens. These pathogens are Escherichia coli O157: H7 NCTC 12900, Salmonella enterica subsp. enterica ATCC 13076, and Listeria monocytogenes ATTC 7644. Also, in vitro induction amount of IL-12 in mouse splenocytes is investigated to evaluate antitumor properties by 19 strains of L. gasseri and L. plantarum along with the development of short-chain fatty acids (SCFA) by 5 strains of L. fermentum and L. acidophilus. Gas Chromatography Flame Ionization Detector (GC-FID) and enzyme-linked immunosorbent assay (ELISA) were used to measure short-chain fatty acids and IL-12, respectively. All strains had high viability under acidic conditions. The highest levels of pancreatin and pepsin resistance were found in strains LF56, LF57, LF55, OF, and F and strains LF56, LF57, and A7, respectively. All strains except LF56 had high resistance to bile salts. L. gasseri 54C had the highest average adhesion score (hydrophobicity) of 62.9 % among 19 strains. Despite the susceptibility of different strains of L. plantarum to the tested antibiotics, M8 and M11, S2G, A7, LF55, LF57, and 5G were resistant to kanamycin and chloramphenicol, respectively. Also, 21G was resistant to ampicillin, LF56 to tetracycline and M8, and M11, LF56, and 21G to Erythromycin. In addition, L. gasseri showed moderate resistance to ampicillin, erythromycin, and tetracycline, while L. fermentum ATCC 9338 showed good resistance to ampicillin, erythromycin, and chloramphenicol. In this respect, L. plantarum LF56 and gasseri 54C had the highest average auto-aggregation and co-aggregation against three pathogenic bacteria, respectively. The highest and lowest levels of acetic acid as short-chain fatty acids were produced by L. fermentum 19SH isolated from Horre 41.62 and L. fermentum 21SH from fermented seeds 27.047, respectively. Moreover, L. fermentum, with the OF code of traditional-fermented food origin, produced the most isobutyric acid, butyric acid, and valeric acid, with values of 0.6828, 0.74165, and 0.49915 mmol, respectively. L. fermentum isolated from the human origin with code F produced the most isovaleric acid of 1.1874 mmol. All the tested strains produced good propionic acid except L. fermentum 21SH from fermented seeds. Among strains, L. plantarum M11 isolated from milk and L. gasseri 52B from humans had the highest in vitro induction of IL-12, which is probably related to their cell wall compositions and structure.

Tuber pathogenicity of Macrophomina phaseolina strain 3a isolated from rotten cassava tuber from farm lands in Osogbo, Osun State, Nigeria, its virulence genes and ADMET properties.

Macrophomina phaseolina is a pathogen that causes an opportunistic disease that spreads by soil and seeds and affects more than 500 different plant species, like fruits, trees, and row crops. Mycotoxins, such as phaseolinic acid, and phaseolinone, are produced by M. phaseolina isolates in previous investigations; however, the production of these mycotoxins seems to vary depending on the host and the region. In this study, Macrophomina phaseolina strain 3A was isolated from rotten cassava tuber and identified using the analysis of the sequences of the internal transcribed spacer region. The isolate was inoculated on a fresh healthy cassava tuber at 25°C and tuber-rotting potential was monitored for 4 weeks. Virulence genes MPH_06603, MPH_06955, and MPH_01521 were determined with designed primers, and secondary metabolites were characterized by FTIR and GCMS. The rotten tuber effect was observed from the 2nd week of the experiment with severe tuber rot and weight reduction. The PCR showed the presence of MPH_06603 virulence gene. The GCMS showed N-Methylpivalamide (115.0m/z), Butane, 1,4-dimethoxy- (119.0m/z), and 5-Hydroxymethylfurfural (126.0m/z) were the predominant metabolites produced by the pathogen. The compounds in the metabolites inhibit CYP3A4 enzymes, cause eye irritation, and Human Ether-a-go-go-related gene inhibition. This study revealed that M. phaseolina was responsible for the cassava tuber rot which leads to a lower yield of farm produce. The metabolites produced are toxic and unsafe for human consumption. It is suggested that farmers should destroy any cassava affected by this pathogen to prevent its toxic effects on humans and animals.

Isolation and Characterization of Potassium-Solubilizing Rhizobacteria (KSR) Promoting Cotton Growth in Saline-Sodic Regions.

Cotton is highly sensitive to potassium, and Xinjiang, China's leading cotton-producing region, faces a severe challenge due to reduced soil potassium availability. Biofertilizers, particularly potassium-solubilizing rhizobacteria (KSR), convert insoluble potassium into plant-usable forms, offering a sustainable solution for evergreen agriculture. This study isolated and characterized KSR from cotton, elucidated their potassium solubilization mechanisms, and evaluated the effects of inoculating KSR strains on cotton seedlings. Twenty-three KSR strains were isolated from cotton rhizosphere soil using modified Aleksandrov medium. Their solubilizing capacities were assessed in a liquid medium. Strain A10 exhibited the highest potassium solubilization capacity (21.8 ppm) by secreting organic acids such as lactic, citric, acetic, and succinic acid, lowering the pH and facilitating potassium release. A growth curve analysis and potassium solubilization tests of A10 under alkali stress showed its vigorous growth and maintained solubilization ability at pH 8-9, with significant inhibition at pH 10. Furthermore, 16S rRNA sequencing identified strain A10 as Pseudomonas aeruginosa. Greenhouse pot experiments showed that inoculating cotton plants with strain A10 significantly increased plant height and promoted root growth. This inoculation also enhanced dry biomass accumulation in both the aerial parts and root systems of the plants, while reducing the root-shoot ratio. These results suggest that Pseudomonas aeruginosa A10 has potential as a biofertilizer, offering a new strategy for sustainable agriculture.

Impact of the tripartite interaction between rice, sheath blight and diverse crop-associated endophytes on phenotypic and biochemical responses in rice

Endophytes stimulate plant growth and inhibit phytopathogens. Most of the known endophytes are host-specific and only a few strains are effective for practical field use. Thus, this study focuses on the evaluation of endophytes viz., Bacillus pseudomycoides strain HP3d, Paenibacillus polymyxa strain PGSS1, B. velezensis strain A6 and P42 isolated from diverse crop ecosystems for their potential to promote plant growth and induce systemic resistance against sheath blight disease in rice. The endophytes were studied for plant growth promoting traits in vivo conditions and were found to exhibit ammonia (light to strong), siderophore (yellow zone on the CAS agar plate), indole-3-acetic acid (15.20–22.19 μg mL−1) production and phosphorus solubilization (1.2–1.5 cm). In the glasshouse, when applied individually and in combinations through various methods like seed treatment, seedling dip, and foliar spray these endophytes significantly reduced lesion size (2.06–2.37 fold) and ShB severity (2.60–2.58 fold), enhancing growth parameters viz., shoot (1.09–1.11 fold), root (1.02–1.20 fold), number of tillers (1.2–1.6 fold), shoot (80.58–82.64 %) and root (62.01–66.66 %) dry matter over untreated control. Consequently, enzyme activity viz., polyphenol oxidase (2.20–3.00 U−1min−1g−1), peroxidase (0.31–0.35 min−1g−1), superoxide dismutase (118.50–123.00 Ug−1 FW), and phenylalanine ammonia lyase (0.84–0.90 min⁻1g⁻1FW) was found to increase up to the fourth day after the pathogen challenge and subsequently decrease thereafter. Chlorophyll content post inoculation of ShB declined over time but endophyte treated plants exhibited lesser reductions over uninoculated control. Field trials corroborated the in vitro findings, demonstrating reduced ShB (1.71–1.88 fold decrease in PDI) and enhanced growth (1.1–1.2 fold increase in shoot length) over untreated controls. The combined application of seedling dip, seed treatment, and foliar spray proved to be the most optimum treatment. The findings highlight the potential of diverse crop-derived endophytes, emphasizing their non-host specificity and effectiveness as broad-spectrum bioagents in actual field conditions.

The role and mechanism of Bacillus megaterium strain A14 in inhibiting the cadmium uptake by peanut plants in acidic red soil.

This study explores the potential of cadmium (Cd)-resistant bacteria, specifically Bacillus megaterium A14, to decrease Cd accumulation in peanuts, a crop susceptible to metal uptake from contaminated soils, by understanding the bacterium's impact on plant Cd absorption mechanisms. Through pot experiments, we observed that A14 inoculation significantly increased peanut biomass under Cd stress conditions, primarily by immobilizing the metal and reducing its bioavailability. The bacterium effectively changed the distribution of Cd, with a notable 46.53% reduction in the exchangeable fraction, which in turn limited the expression of genes related to Cd transport in peanuts. Additionally, A14 enhanced the plant's antioxidant response, improving its tolerance to stress. Microbial analysis through 16S sequencing demonstrated that A14 inoculation altered the peanut rhizosphere, particularly by increasing populations of Firmicutes and Proteobacteria, which play crucial roles in soil remediation from heavy metals. The A14 strain effectively counters Cd toxicity in peanuts, promoting growth through soil Cd sequestration, root barrier biofilm formation, antioxidant system enhancement, suppression of Cd transport genes, and facilitation of Cd-remediating microorganisms.

Effects affecting ammonia removal in synthetic wastewater by locally isolated Rhodobacter sp strain A1

This research focused on the effects affecting ammonia removal in synthetic wastewater by Rhodobacter sp. strain A1 using one factor at a time method (OFAT). Rhodobacter sp. strain A1 are able to remove ammonia from synthetic wastewater due to its ability to assimilate ammonia. The ammonia removal experiment was conducted under different factors; Rhodobacter sp. strain A1 inoculum size (2%, 4%, 6%), incubation temperature (20°C, 25°C, 30°C, 37°C, 40°C), initial pH of synthetic wastewater (5,6,7,8,9) and initial NH4Cl concentration (5 mg/L, 10 mg/L, 15 mg/L) for four days of incubation period. Then, the solution was tested using Nessler reagent which will produce yellow colour when it reacts with ammonia. The intensity of colour is proportional to the ammonia concentration. This experiment was followed by ammonia quantitative analysis via spectrophotometer at 425 nm. The results obtained were then calculated to get the percentage of ammonia removal by PNSB. The result revealed that the bacterium can achieved 97.90 % efficiency of total ammonia removal at optimum growth condition with 6% of inoculum size, incubation temperature at 30°C and initial pH 7. As a conclusion, this Rhodobacter sp. strain A1 can therefore serve as a good candidate in wastewater treatment for ammonia removal.

Biological control of Spodoptera frugiperda J.E. Smith and Schistocerca piceifrons piceifrons Walker using entomopathogenic fungi

ctive: Evaluate the biological effectiveness of native entomopathogenic fungi to control Spodoptera frugiperda and Schistocerca piceifrons piceifrons, as well as the natural incidence of parasitoids in S. frugiperda.
 Design/Methodology/Approach: Six strains of Metarhizium anisopliae (A1, A2, A3, A4, A5, and A6) and three strains of Isaria fumosorosea (B4, B5, and B6) were collected. S. frugiperda larvae were inoculated with all the isolated strains of Metarhizium and Isaria; while, the nymphs of S. p. piceifrons were inoculated with strains A1, A5, A6, B4, and B5. Mortality (%) and natural incidence of parasitoids in S. frugiperda larvae were evaluated. Mortality was analyzed using a one-way ANOVA and a comparison of means (Duncan; ɑ = 0.05) in the INFOSTAT 2021 software. Parasitism was reported with descriptive statistics (%).
 Results: Strains A1, A6, and B6 caused the highest mortality (86.6-90.0 %) in S. frugiperda larvae. Strains A1, A5, A6, and B6 caused the highest mortality in nymphs of S. p. piceifrons (90-100 %). Two families of parasitoids were recorded: Tachinidae (Diptera; 7.8 %) and Braconidae (Hymenoptera). Wasps of the genus Meteorus sp. account for 92.2 % of the latter family.
 Study Limitations/Implications: The biological effectiveness evaluations of the entomopathogenic fungi were carried out under laboratory conditions. The results must still be validated on the field.
 Findings/Conclusions: Strains A1, A5, and A6 showed a good control of the S. p. piceifrons nymphs. Strain B6 is a biological control alternative for S. p. piceifrons and S. frugiperda, since it recorded the highest mortality for both species.

Defluorination of PFAS by Acidimicrobium sp. strain A6 and potential applications for remediation.

Acidimicrobium sp. strain A6 is a recently discovered autotrophic bacterium that is capable of oxidizing ammonium while reducing ferric iron and is relatively common in acidic iron-rich soils. The genome of Acidimicrobium sp. strain A6 contains sequences for several reductive dehalogenases, including a gene for a previously unreported reductive dehalogenase, rdhA. Incubations of Acidimicrobium sp. strain A6 in the presence of perfluorinated substances, such as PFOA (perfluorooctanoic acid, C8HF15O2) or PFOS (perfluorooctane sulfonic acid, C8HF17O3S), have shown that fluoride, as well as shorter carbon chain PFAAs (perfluoroalkyl acids), are being produced, and the rdhA gene is expressed during these incubations. Results from initial gene knockout experiments indicate that the enzyme associated with the rdhA gene plays a key role in the PFAS defluorination by Acidimicrobium sp. strain A6. Experiments focusing on the defluorination kinetics by Acidimicrobium sp. strain A6 show that the defluorination kinetics are proportional to the amount of ammonium oxidized. To explore potential applications for PFAS bioremediation, PFAS-contaminated biosolids were augmented with Fe(III) and Acidimicrobium sp. strain A6, resulting in PFAS degradation. Since the high demand of Fe(III) makes growing Acidimicrobium sp. strain A6 in conventional rectors challenging, and since Acidimicrobium sp. strain A6 was shown to be electrogenic, it was grown in the absence of Fe(III) in microbial electrolysis cells, where it did oxidize ammonium and degraded PFAS.

Improved application of immobilized Enterobacter cloacae into a bio-based polymer for Reactive Blue 19 removal, an eco-friendly advancement in potential decolorizing systems.

The widespread use of highly complex synthetic dyes like reactive dyes in the textile industry has some adverse environmental impacts and deserves close attention. Biological treatment of these effluents utilizing various species of bacteria with remarkable efficiency in dye removal is still considered promising. Our current study deals with immobilizing an isolated bacterial strain into calcium alginate (Ca/Alg) gel beads and using it to treat pernicious pollutants like synthetic dyes. A potential Reactive Blue 19 (RB19)-degrading Enterobacter cloacae strain A1 was isolated from the Kashan textile industry and was characterized by 16S rDNA gene sequencing. The decolorization ability of strain A1 was assessed by time-based studies using free bacterial cells/immobilized in Ca/Alg. Based on the results of the 16S rDNA gene sequencing, it appears that strain A1 belonged to E.cloacae, with a 99.74% similarity. The findings suggest that immobilized strain A1 accomplished maximum decolorization activity compared with the free cells. The immobilized strain could utterly decompose and decolorize 0.05 mg/mL of RB19 within 48 h, while the free bacterial strain decolorized RB19 within 5 days. Moreover, Ca/Alg gel beads can maintain their efficiency for over three decolorization cycles. Further infrared spectroscopy (FTIR) and gas chromatograph mass spectrometer (GC/MS) investigation declared complete RB19 decomposition on reaction products. Artemia salina was used to investigate the toxicity of dye and its degraded metabolites. The LC50 values signified the pure dye as very toxic with 0.01 mg/mL concentration, while after-treatment products showed no toxic effect on larvae. This immobilization technique increased the applicability of bacterial strain for dye removal. It was beneficial for the decolorization of RB19 from textile wastewater due to a remarkable reduction in time. Notably, strain A1-immobilized beads can maintain their activity for three consecutive decolorization cycles without a considerable decrease in efficiency. PRACTITIONER POINTS: The remarkable capacity of immobilized Enterobacter cloacae strain A1 for Reactive Blue 19 (RB19) removal Immobilized A1 strain showed two-fold higher removal than free one over 48 h A promising method for enhancing RB19 decolorization Decolorization was due to degradation based on UV-Vis, FTIR, and GC/MS analysis Non-toxic posttreatment products for Artemia.

Development of an efficient Agrobacterium-mediated transformation method and its application in tryptophan pathway modification in Catharanthus roseus.

The biosynthetic pathway of Catharanthus roseus vinca alkaloids has a long research history, including not only identification of metabolic intermediates but also the mechanisms of inter-cellular transport and accumulation of biosynthesized components. Vinca alkaloids pathway begins with strictosidine, which is biosynthesized by condensing tryptamine from the tryptophan pathway and secologanin from the isoprenoid pathway. Therefore, increasing the supply of precursor tryptophan may enhance vinca alkaloid content or their metabolic intermediates. Many reports on the genetic modification of C. roseus use cultured cells or hairy roots, but few reports cover the production of transgenic plants. In this study, we first investigated a method for stably producing transgenic plants of C. roseus, then, using this technique, we modified the tryptophan metabolism system to produce transgenic plants with increased tryptophan content. Transformed plants were obtained by infecting cotyledons two weeks after sowing with Agrobacterium strain A13 containing a plant expression vector, then selecting with 1/2 B5 medium supplemented with 50 mg l-1 kanamycin and 20 mg l-1 meropenem. Sixty-eight regenerated plants were obtained from 4,200 cotyledons infected with Agrobacterium, after which genomic PCR analysis using NPTII-specific primers confirmed gene presence in 24 plants with a transformation rate of 0.6%. Furthermore, we performed transformation into C. roseus using an expression vector to join trpE8 and aroG4 genes, which are feedback-resistant mutant genes derived from Escherichia coli. The resulting transformed plants showed exactly the same morphology as the wild-type, albeit with a marked increase in tryptophan and alkaloids content, especially catharanthine in leaves.