Indigenous Isolates Research Articles

Indigenous Trichoderma isolates from Bukit Kijang, North Sumatra, Indonesia, are biocontrol agents against Ganoderma boninense in infected oil palm seedlings

Basal stem rot, caused by Ganoderma boninense is a serious disease in oil palm plantations in North Sumatra, Indonesia. However, the use of fungicides to control this pathogen can cause instability in terrestrial ecosystems and decrease the number of beneficial microorganisms. Therefore, identifying other effective and environmentally friendly control methods, such as Trichoderma, is essential. Trichoderma was previously isolated from the leaf, rachis, stem, and root tissues of oil palms but not from the rhizosphere soil. Therefore, this study aimed to assess the potency of indigenous Trichoderma isolates from the rhizosphere soil of oil palm seedling plantations in Bukit Kijang, North Sumatra, Indonesia, as biocontrol agents to reduce G. boninense infection. Four Trichoderma isolates were isolated from healthy oil palm rhizospheres in Bukit Kijang and screened in vitro. Based on molecular identification, the Trichoderma isolates were identified as T. asperellum1, T. virens1, T. asperellum2, and T. virens2. All Trichoderma species inhibited the development of Ganoderma and stimulated the vegetative growth of oil palm seedlings. Therefore, T. asperellum and T. virens can be used as biocontrol agents to control G. boninense and stimulate the vegetative growth of oil palm seedlings. To our knowledge, this is the first report of indigenous Trichoderma isolates from Bukit Kijang that can be used as biocontrol agents to control G. boninense.

Characterization of Pectinase Enzyme Produced from Indigenous Yeast Isolates During Fermentation of Robusta Coffee Beans

The following research aims to understand indigenous yeast isolates that are pectinolytic, the effect of incubation time on pectinase enzyme activity, and the pH and temperature properties of pectinase enzymes obtained from indigenous yeasts from spontaneous fermentation of robusta coffee beans. The following type of research is an experiment through RAL (Completely Randomized Design). The results showed that testing of seven indigenous yeast isolates was pectinolytic and that the highest pectinolytic ability was isolate K24I7 with a clear zone diameter of 3.13 mm. The characterization results of the pectinase enzyme produced from isolate K24I7 were optimum at pH 5.5 with an enzyme specific activity value of 10.09 U/mg and optimum temperature in the range of 40oC-60oC with an average enzyme specific activity of 10.08 U/mg. The pectinase enzyme produced from isolate K24I7 is thermophile because it is still active at 70°C

Alleviating arsenic stress affecting the growth of Vigna radiata through the application of Klebsiella strain ASBT-KP1 isolated from wastewater.

Arsenic contamination of soil and water is a major environmental issue. Bioremediation through plant growth-promoting bacteria is viable, cost-effective, and sustainable. Along with arsenic removal, it also improves plant productivity under stressful conditions. A crucial aspect of such a strategy is the selection of bacterial inoculum. The described study demonstrates that the indigenous wastewater isolate, ASBT-KP1, could be a promising candidate. Identified as Klebsiella pneumoniae, ASBT-KP1 harbors genes associated with heavy metal and oxidative stress resistance, production of antimicrobial compounds and growth-promotion activity. The isolate efficiently accumulated 30 μg/g bacterial dry mass of arsenic. Tolerance toward arsenate and arsenite was 120 mM and 70 mM, respectively. Plant biomass content of Vigna radiata improved by 13% when grown in arsenic-free soil under laboratory conditions in the presence of the isolate. The increase became even more significant under the same conditions in the presence of arsenic, recording a 37% increase. The phylogenetic analysis assigned ASBT-KP1 to the clade of Klebsiella strains that promote plant growth. Similar results were also observed in Oryza sativa, employed to assess the ability of the strain to promote growth, in plants other than V. radiata. This study identifies a prospective candidate in ASBT-KP1 that could be employed as a plant growth-promoting rhizoinoculant in agricultural practices.

Evaluation of Different Lactic Acid Bacteria as Starter Cultures for Nono—A West African Fermented Dairy Product

Nono is a traditional cultured dairy product consumed across West Africa. In this study, five cultures isolated from Nigerian-produced nono and three purified lactic acid bacteria from the USDA-NRRL were examined for use in preparing nono starter cultures. Isolated cultures were characterized using microbiological and biochemical tests, including 16s rDNA sequencing to identify the genotype. Each isolated strain was cultured and inoculated into UHT milk (1% v/v) and allowed to ferment for 24 h at 25 °C. Fermented products were evaluated for pH, moisture content, water activity, and viscosity, and their descriptive sensory properties were noted. The isolate that resulted in sensory properties most similar to traditional nono was then used as the primary strain for subsequent starter culture blends made with the NRRL cultures. These blends were used for the fermentation of nono and compared with commercial nono samples. Isolates obtained from nono were as follows: Lactobacillus fermentum, Lactobacillus paracasei, and, surprisingly, Lactobacillus rhamnosus, which has not been previously reported as a part of the nono microflora. There was no significant difference in the physical parameters of nono made from the individual indigenous isolates and a similar pattern was observed for the organisms from NRRL, except that their total titratable acidity and viscosities were significantly (p < 0.05) higher than those of the indigenous organisms. Compounded starter made with L. rhamnosus and NRRL cultures was then used to make nono that showed significantly (p < 0.05) different pH and viscosity values than commercially purchased nono, while sensory evaluation showed that nono made from the new starter culture had a high overall consumer acceptance score.

Enhanced biodegradation of lignin and lignocellulose constituents in the pulp and paper industry black liquor using integrated magnetite nanoparticles/bacterial assemblage

The study was designed to explore the efficiency of magnetite nanoparticles (Fe3O4 NPs)/bacterial cell assembly to biodegrade lignin and lignocellulose, decontaminate pulp and paper-contaminated wastewater and optimize lignin adsorption by Fe3O4 NPs. Water samples were collected from three paper and carton manufacturing companies, Alexandria Governorate, Egypt. Pseudomonas otitidis MCC10330, the most active and promising strain among 10 previously screened indigenous and exogenous isolates, was selected and decorated with magnetic Fe3O4 Nanoparticles, that were prepared by the co-precipitation method, characterized and used to decontaminate paper and pulp effluent in a batch mode bioassay for 4 h. Fe3O4 NPs/bacterial cell assembly achieved the highest removals (64.1, 52.0, 54.3 and 66.6%) of TSS, COD, BOD, and Total Tannin and Lignin after 1, 4 and 4 h, reaching residual concentrations (RCs) of 322, 216, 112 and 7 mg/L, which are still slightly higher (5.35, 2.7 and 1.86-fold) than their maximum permissible limits (MPLs), respectively. RCs of pH, DO and TDS in the treated effluent are accepted for safe discharging. Maximum lignin adsorption and removal (82.14%) using Fe3O4 NPs was achieved at the optimized conditions (pH 6, Fe3O4 NPs dosage of 100 mg and 10 min contact time). Results confirmed that the proposed magnetite-coated Pseudomonas otitidis treatment system is highly efficient and recommended to treat the highly contaminated pulp and paper wastewater. Also, as far as we know, this integrated assemblage is the first time to be used as a novel, very promising, eco-friendly, renewable and economical biotechnological approach to minimize/eliminate the involved pollutants with the least running time.

Effectiveness Test of Indigenous Plant Growth Promoting Rhizobacteria (PGPR) Isolate on the Growth of Acehnese Patchouli (Pogostemon cablin Benth.) Sidikalang Variety

Plant Growth Promoting Rhizobacteria (PGPR) is a group of bacteria that live saprophytically in the root area (rhizosphere) acting as a plant growth promoter. The purpose of this study was to test the effectiveness of indigenous rhizobacterial isolates from Aceh Besar and Aceh Tengah in supporting the growth of Aceh patchouli Sidikalang variety. This research was conducted at the Laboratory of Seed Science and Technology, Faculty of Agriculture, Syiah Kuala University and patchouli planting was carried out at the Patchouli Innovation Park (Nino Park), Syiah Kuala University, which took place from December 2022 to June 2023. This study used a non-factorial Randomized Group Design (RAK) with 3 replications. The factor studied was the type of rhizobacterial isolate consisting of 15 treatment levels, namely 1 treatment without rhizobacteria, 7 treatments given indigenous rhizobacterial isolates from Lambada, Seulimeum District, Aceh Besar Regency and 7 treatments given rhizobacterial isolates from Paya Tampu village, Rusip Antara District, Central Aceh Regency. The observation parameters studied are of plant height, number of leaves, number of branches, stem diameter, area per leaf blade, root length, root volume and wet biomass weight of plants. The results showed that indigenous rhizobacterial isolates from Aceh Besar and Aceh Tengah effectively increased the average plant height of Sidikalang variety patchouli at 4 and 8 MSA (26%, and 24%), number of leaves (46%, and 58%), number of branches (78% and 50%), area per leaf blade (34%), root length (19%), root volume (60%) and plant wet biomass weight (50.61%).

<i>Bacillus thuringiensis</i> Isolates and their Cry Genes Toxic to Chickpea Pod Borer <i>Helicoverpa armigera</i> (Hubner) from Ethiopia

Helicoverpa armigera (Hubn) is one of the most destructive insect pests of chickpea in Ethiopia. For sustainable management of insect pests of food crops, Bacillus thuringiensis (Bt) is a widely used bioinsecticide. This study was aimed at exploring indigenous Bt isolates that harbour cry genes to control H. armigera. Ten indigenous Bt isolates were analyzed for their cry genes. Accordingly, all the indigenous Bt isolates were observed to harbour two or more cry genes. Statistically significant (p<0.05) variations were observed among Bt species in influencing larval incidence, pod damage (%) and grain yield (t/ ha). Three potential indigenous Bt isolates were identified with their respective cry genes that included KDL (cry2 + cry4), AUGHS-1 (cry1 + cry4), and AUSD-1 (cry1 + cry2 + cry4 + cry7, 8 + cry9). Indigenous Bt isolates exhibited a strong potential in the management of chickpea pod borer. Development of commercial bioinsecticide and other Bt technologies using B. thuringiensis from Ethiopian sources will be a new avenue to be addressed.

Isolation, screening, and molecular characterization of indigenous Trichoderma isolates from West Java, Indonesia and their plant growth-promoting capability on rice plants (Oryza sativa L.)

Trichoderma species are widely acknowledged as growth-promoting fungi that have been utilized to enhance the growth and yield of numerous crops. This research examined the capacity of 30 Trichoderma strains, isolated from two organic rice fields in West Java, Indonesia, to enhance the germination, growth, and physiological characteristics of rice plants (Oryza sativa L.). In general, Trichoderma strain TM10 demonstrated the greatest ability to increase seed germination (97.25 %), vigor index (3122.83), and germination speed (59.91 seeds/day). This strain also increased seedling root length and seedling height by 101.62 % and 112.20 %, respectively. Plants treated with TM10 exhibited a notable improvement in root length, plant height, fresh weight, and dry weight compared to control plants, demonstrating increases of 188.68 %, 69.90 %, 157.41 %, and 159.38 %, respectively. Furthermore, the total chlorophyll content and stomatal number in TM10-treated plants exhibited increments of 75.23 % and 75.53 %, respectively. Five selected isolates (TM7, TM10, SB2, SB8, and SB14) were evaluated for their potential to produce plant growth-promoting compounds, including phosphatase enzyme (ranging from 0.54 to 11.14 µg pNP g−1h−1), indole-3-acetic acid (IAA) (ranging from 28.96 to 63.91 µg/mL), ammonia (ranging from 1.96 to 5.79 µg/mL), and hydrogen cyanide (HCN) (ranging from 221.76 to 274.82 ppm). The best strain, namely TM10, was then molecularly identified as Trichoderma yunnanense. This investigation demonstrates that Trichoderma spp. isolated from organic rice fields could be used as a bioinoculant in sustainable rice production.

Selection of indigenous Saccharomyces cerevisiae strains with good oenological and aroma characteristics for winemaking in Ningxia China

Ningxia is one of the well-known wine producing regions in China. However, the oenological and aroma characteristics of indigenous yeasts remains hidden. The fermentative and oenological properties including stress resistance, hydrogen sulfide, foam production levels; killer phenotype, and flocculation of 89 Ningxia indigenous Saccharomyces cerevisiae isolates and ten commercial yeasts were evaluated. The fermentative and oenological properties of the tested strains varied significantly. They could resist 500 g/L glucose, 300 mg/L SO2, 14% (v/v) ethanol and pH 2.8, and produce more esters. They also produce low levels of ethanol and could conduct fermentations vigorously and at a high rate. Cabernet Sauvignon wines made with NXU 21–24 showed the high intensity of tropical fruit, dry fruit, temperate fruit, and spicy flavor. The floral flavor in NXU 21–102 fermented wine is very intense. The indigenous S. cerevisiae strains of NXU 21–102 and NXU 21–24 exhibited potential use as starter cultures in wine production.

PCR-based detection and mutation dynamics of fusion protein gene of orthoaviula viruses sequestered during 2023 field outbreaks in Pakistan

: To isolate and detect a Newcastle disease virus in commercial poultry, Molecular characterization and phylogenetic analysis of the confirmed isolate and Multiple sequence alignment and achievement of accession numbers against our submissions in NCBI bankit.: Genetic and antigenic diversity in the fusion protein gene of New Castle disease virus strains has been recognized and the progressive changes over sequential years indicate that it is a continuously evolving virus. The current vaccines containing conventional vaccinal strains can protect birds to a certain level but do not prevent infection and virus shedding. : The partial fusion protein gene of the 14 NDV isolates during the 2023 outbreaks from different areas of Pakistan was determined and analyzed. The antigenic protein translational segment of the fusion gene nucleotide fragment was targeted with a specifically designed primer executed 202 bp size of predictable amplicon during PCR amplification. The nucleotide sequence analysis of studied isolates showed closed similarity to the NCBI bankit numbers. Phylogenetic analysis revealed that 3 isolates belong to genotype II while, 2 isolates positions near genotype VIII of class II. The 6 isolates were located near genotype XVII and only 1 was presented on genotype V branch in calss II. Mutation analysis results revealed various mutations at nucleotide intervals and even found altered amino acids during translation. The results revealed that nucleotide mutation at various positions attributes amino acid substitution that enables wild prevailing strains to evade artificial active immunity. In such a scenario Chimeric and genotype match vaccines prepared from indigenous isolates may be useful in developing candidate vaccines to prevent virus shedding and infection. Further studies are suggested at molecular level to determine the consensus amino acid sequence for virulent, mesogenic, and avirulent prevailing NDV strains.

Molecular Characterisation and Toxicity Analysis of Indigenous Bacillus thuringiensis Berliner Isolates against Cucurbit Fruit Fly Maggots, Zeugodacus cucurbitae (Coquilett) (Diptera: Tephritidae)

Background: Indiscriminate use of insecticides against fruit flies (Tephritidae: Diptera) has led to the development of residue and resistance and there is a need to try alternate eco-friendly management practices. Bacillus thuringiensis (Bt) is the most widely used bacterium forming proteins active against insects of different orders. Thus, the present study was framed to characterize and evaluate 50 indigenous Bt isolates against cucurbit fruit fly maggots, Zeugodacus cucurbitae. Methods: Colony morphology was observed visually, while crystal morphology was observed through a microscope. The cry gene content of the Bt isolates was screened by Polymerase Chain Reaction and the proteins harbored were assessed by SDS- PAGE analysis. Full diet contamination method was used to evaluate the toxicity of Bt isolates against cucurbit fruit fly maggots. Result: Uniform full white, off-white and creamy white colony colours were found except one isolate each, exhibiting full white at centre surrounded by off white and off white at centre surrounded by full white. Spherical shape crystal (45.10%) was predominant followed by cuboidal (29.41%), bipyramidal (17.65%), rectangular (3.92%) and minute crystal attached to spore (3.92%). Insecticidal proteins varied from ~15 to greater than 200kDa in size with one to four and more distinct bands per isolate. PCR screening revealed cry4Aa in 2 isolates, cry4Ba and cry11Aa in one isolate each, cyt1 in 1 isolate. The standard strain Bti 4Q2 (100% mortality of maggots) and the indigenous Bt isolates, T166 (92.59%), T184 (91.11%) and T60 (90.48%) were found to be significantly toxic.

Antibiotic Indexing and Heavy Metal Reduction Potential of Four Multi-metal Tolerant Bacterial Strains in Real-Time Sanitary Landfill Leachate Matrix.

Sanitary leachate from urban landfills is known to be contaminated with multi-metals and residual antibiotics. Current research edges on exploring the multi-metal and antibiotic sensitivity profile of four indigenous strains, "Brevibacillus spp. Leclercia spp. Pseudescherichia spp., and Brucella spp." isolated from the leachate of a sanitary landfill in a tropical region. Indigenous isolates were observed to be antibiotic-resistant and have high tolerance against eight of the ten tested metals except Cu & Co. It was observed that interaction with multi-metals in laboratory conditions significantly altered the cell morphology of bacterial strains, as depicted by Scanning Electron Microscope. Metal adsorption onto the microbial surface was deciphered through Electron Dispersive Spectrometer analysis and elemental mapping. Application of isolated strains into real-time leachate matrix exhibits a complete reduction of Ag and Zn and for other tested metals. Their response to these toxicants may facilitate their application in bioremediation-based treatment technologies for urban landfill leachate.

Genotyping and Phenotyping of Indigenous Saccharomyces cerevisiae from a New Zealand Organic Winery and Commercial Sources Using Inter-Delta and MALDI-TOF MS Typing.

We used inter-delta typing (IDT) and MALDI-TOF profiling to characterize the genetic and phenotypic diversity of 45 commercially available winemaking Saccharomyces cerevisiae strains and 60 isolates from an organic winemaker from Waipara, New Zealand, as a stratified approach for predicting the commercial potential of indigenous isolates. A total of 35 IDTs were identified from the commercial strains, with another 17 novel types defined among the Waipara isolates. IDT 3 was a common type among strains associated with champagne production, and the only type in commercial strains also observed in indigenous isolates. MALDI-TOF MS also demonstrated its potential in S. cerevisiae typing, particularly when the high-mass region (m/z 2000-20,000) was used, with most indigenous strains from each of two fermentation systems distinguished. Furthermore, the comparison between commercial strains and indigenous isolates assigned to IDT 3 revealed a correlation between the low-mass data (m/z 500-4000) analysis and the recommended use of commercial winemaking strains. Both IDT and MALDI-TOF analyses offer useful insights into the genotypic and phenotypic diversity of S. cerevisiae, with MALDI-TOF offering potential advantages for the prediction of applications for novel, locally isolated strains that may be valuable for product development and diversification.

Bioprospecting of Indigenous Microbial Species for Bioethanol Production from the Fruits of Some Selected Exotic Ornamental Plants

The study determined the ability of some selected indigenous microbial isolates, namely Bacillus subtilis, Zymomonas mobilis and Saccharomyces cerevisiae, in the production of bioethanol from the fruits of some exotic plants (i.e. Ixora coccinea, Duranta repens and Syzygium guineense). B. subtilis was isolated from soil, while Z. mobilis and S. cerevisiae were isolated from palm wine using cultural methods. The organisms were identified based on their colony characteristics and morphological features, which were observed by microscopic examination of the stained smears of the isolates. The identity of the organisms was confirmed through the molecular study of the 16S rRNA and 18S rRNA regions of the microbial genomes using Polymerase Chain Reaction – Denaturing Gradient Gel Electrophoresis (PCR - DGGE). The fruit samples were collected, washed, blended, filtered using a clean piece of cloth and pretreated using ultrasonication and autoclave. Concentrations of reducing sugars in the fruit filtrates were determined using DNSA-UV-visible spectrophotometry. Seven (7) conical flasks (500ml capacity) were arranged for each fruit sample in duplicate, and 250ml of the fruit filtrates were dispensed in the flasks accordingly. The fermenting organisms were inoculated in the flasks containing the fruit filtrates singly and in combination. Flasks were incubated in shaking incubator for seven days at 35oC. After incubation, the concentrations of bioethanol produced were determined using the UV-visible spectrophotometry. Highest reducing sugars concentrations of 43.7% and 43.6% were found in I. coccinea and S. guineense, respectively, while 36.4% was recorded for D. repens. Highest bioethanol yield of 27.5m/L was found in I. coccinea fermented by S. cerevisiae and Z. mobilis, while the lowest yield of 17.25m/L was found D. repens. The yield in bioethanol production was higher in samples containing a combination of fermenting organisms compared to ones with individual cells. It was recommended that the fruits of these exotic plants should be considered for commercial production of bioethanol.

An assessment of various disinfectants using the Kirby-Bauer Method with disc diffusion to determine their effectiveness against locally isolated pathogens

This study aimed to assess the effectiveness of various disinfectants against locally isolated pathogens using the Kirby-Bauer Method with disc diffusion. Indigenous strains of Salmonella typhimurium, E. coli, Campylobacter, Citrobacter freundii, and Staphylococcus aureus were obtained from the bacterial depository bank and sub-cultured on their respective selective media. A 0.5 McFarland Turbidity Standard was prepared, and eight commercially available disinfectants were tested for efficacy. The results of this study will inform the selection of appropriate disinfectants for use in preventing the spread of disease in various settings, including home sanitation, healthcare, and industrial manufacturing processes. The disinfectants used in this study produced different results against the targeted pathogens. Hydrogen peroxide and Formalin produced larger zones of inhibition, while Povidone Iodine and Hydrochloric acid produced intermediate zones. Ethanol, Methanol, and Dettol produced smaller .zones of inhibition. Benzalkonium Chloride was effective only against S. aureus, while all other indigenous isolates resisted it. Keywords: Disinfectants, Sal. typhimurium, E.coli, Campylobacter, Citrobacter freundii, Staphylococcus auerus, Antibiotic sensitivity test

Isolation, molecular identification, and efficacy of indigenous entomopathogenic fungus isolates against Tribolium confusum (Coleoptera: Tenebrionidae) larvae and adults

Isolation, molecular identification, and efficacy of indigenous entomopathogenic fungus isolates against Tribolium confusum (Coleoptera: Tenebrionidae) larvae and adults

Molecular and aflatoxigenicity analyses of Aspergillus flavus isolates indigenous to grain corn in Malaysia; potentials for biological control.

The present work aimed to distinguish the indigenous Aspergillus flavus isolates obtained from the first (pioneer) grain corn farms in Terengganu, Malaysia, into aflatoxigenic and non-aflatoxigenic by molecular and aflatoxigenicity analyses, and determine the antagonistic capability of the non-aflatoxigenic isolates against aflatoxigenic counterparts and their aflatoxin production in vitro. Seven A. flavus isolates previously obtained from the farms were characterized molecularly and chemically. All isolates were examined for the presence of seven aflatoxin biosynthesis genes, and their aflatoxigenicity were confirmed using high performance liquid chromatography with fluorescence detector (HPLC-FLD). Phylogenetic relationships of all isolates were tested using ITS and β-tubulin genes. Of the seven isolates, two were non-aflatoxigenic, while the remaining were aflatoxigenic based on the presence of all aflatoxin biosynthesis genes tested, and the productions of aflatoxins B1 and B2. All isolates were also confirmed as A. flavus following phylogenetic analysis. The indigenous non-aflatoxigenic isolates were further examined for their antagonistic potential against aflatoxigenic isolates on 3% grain corn agar (GCA). Both non-aflatoxigenic isolates significantly reduced AFB1 production of the aflatoxigenic isolates. The indigenous non-aflatoxigenic A. flavus strains identified in the present work were effective in controlling the aflatoxin production by the aflatoxigenic A. flavus isolates in vitro and can be utilized for in situ testing.

Statistical optimization of bioprocess parameters for enhanced production of bacterial cellulose from K. saccharivorans BC-G1.

Bacterial Cellulose (BC) offers a wide range of applications across various industries, including food, biomedical, and textiles, owing to its distinctive properties. Its unique 3D reticulated network of cellulose nanofibers, imparts excellent mechanical qualities, a high water-holding capacity, and thermal stability. Additionally, it possesses remarkable biocompatibility, biodegradability, high crystallinity, and purity. These attributes have offered significant interest in BC within both academic and industrial sectors. However, BC production is associated with high costs due to the use of expensive growth media and low yields. The study reports the potential of our indigenous isolate, Komagataeibacter saccharivorans BC-G1, as BC producer. Statistical optimization of BC production was carried out using Placket-Burman design and Central composite design, by selecting different parameters. Eight significant factors such as temperature, pH, glucose, yeast, peptone, acetic acid, incubation time and % inoculum were studies using ANOVA-based response surface methodology. Results showed that BC yield (8.5g/L) with 1.8-fold after optimization of parameters. Maximum cellulose production (8.5 ± 1.8g/L) was obtained using 2% glucose, 0.3% yeast extract, 0.3% peptone, 0.75% (v/v) acetic acid at pH 7.0 for 10 days of incubation with 4% inoculum at 25°C under static culture. Main effect graph showed incubation time and acetic acid concentration as the most significant parameters affecting BC production in our study. The physicochemical characterization of produced BC was done using FTIR, XRD and SEM techniques.

Response of Two True Shallot Seed Varieties to Indigenous Arbuscular Mycorrhizal Fungi Inoculation

Seed availability poses a significant challenge for farmers, and True Shallot Seed (TSS) derived from seeds offers a potential solution to this problem. Currently, farmers primarily rely on bulb seeds for shallot cultivation. Therefore, extensive research on TSS seeds is crucial. This study aimed to investigate the impact of different indigenous FMA isolate types on the growth of various shallot varieties derived from seeds and the root infection of shallot plants. The research was conducted at the Wire House of the Faculty of Agriculture, Andalas University. A completely randomized design with two factors, namely the variety type and FMA dose, was employed, with three replications. The Lokananta and Sanren varieties were used, and the doses of FMA applied were 0, 10, 20, and 30 g/plant. The findings revealed no interaction between the variety type and FMA dose. The Sanren variety outperformed the Lokananta variety in plant height, number of leaves, percentage of root infection, root fresh weight, and root volume. Additionally, the FMA dose of 30 g/plant yielded better results regarding root fresh weight and volume.

Phenotypic characterization for bioremediation suitability of isolates from Southern Tunisian tannery effluent

Effluents from the leather tanning industry contain diverse pollutants, including hazardous heavy metals, posing threats to public health and the surrounding environment. Indigenous bacterial isolates can represent an eco-friendly approach for tannery wastewater treatment; however, phenotypic characterization is necessary to determine whether these strains are suitable for bioremediation. In the present study, we analyzed seven new Enterococcus faecium strains and two new Bacillus subtillis strains isolated from effluents from the Southern Tunisian Tannery (ESTT). We evaluated phenotypic features beneficial for bioremediation, including biofilm formation, hydrophobicity, and exoenzyme activities. Additionally, we examined characteristics naturally occurring in environmental bacteria but less desirable in strains selected for bioremediation, such as antibiotic resistances and pathogenicity indicators. The observed phenotypes were then compared with whole-genome analysis. We observed biofilm production in two slime-producing bacteria, B. licheniformis RLT6, and E. faecium RLT8. Hydrophobicity of E. faecium strains RLT1, RLT5, RLT8, and RLT9, as well as B. licheniformis RLT6 correlated positively with increasing ESTT concentration. Exoenzyme activities were detected in E. faecium strains RLT2, RLT4, and RLT7, as well as B. licheniformis RLT6. As anticipated, all strains exhibited common resistances to antibiotics and hemolysis, which are widespread in nature and do not hinder their application for bioremediation. Importantly, none of the strains exhibited the pathogenic hypermucoviscosity phenotype. To the best of our knowledge, this is the first report consolidating all these phenotypic characteristics concurrently, providing a complete overview of strains suitability for bioremediation. ImportanceThe study evaluates the bioremediation potential of seven Enterococcus faecium strains and two Bacillus subtillis strains isolated from the effluents from the Southern Tunisian tannery (ESTT), which pose threats to public health and environmental integrity. The analysis primarily examines the phenotypic traits crucial to bioremediation, including biofilm formation, hydrophobicity, and exoenzyme activities, as well as characteristics naturally occurring in environmental bacteria related to heavy metal resistance, such as antibiotic resistances. Several strains were found to have high bioremediation potential and exhibit only antibiotic resistances commonly found in nature, ensuring their application for bioremediation remains uncompromised. The results of the exhaustive phenotypic analysis are contrasted with the whole genome sequences of the nine strains, underscoring the appropriateness of these bacterial strains for eco-friendly interventions in tannery wastewater treatment.