Salt Medium Research Articles

Effect of salt concentration on osmotic potential in drying soils—Measurement and models

AbstractThe water potential in drying soils, comprising both matric potential and osmotic potential components, can be measured using the dew point method (DPM). By combining DPM data with retention curve data acquired from techniques such as the suction plate method or the simplified evaporation method (SEM), it becomes possible to determine the soil water retention curve across the entire moisture spectrum. However, as the latter methods only determine the matric potential, the osmotic potential component in DPM data must either be negligible or known so that osmotic and matric potential components can be separated. This study aims to critically analyse common approaches for calculating the osmotic potential. To achieve this, we measured the water retention properties of a silt loam, a sandy loam and a sand across the entire moisture range by combining SEM and DPM. By using almost salt‐free soil material, we characterized reference water retention curves with negligible osmotic potential components. The impact of salt on water potential was analysed by conditioning soils with MgCl2 solutions of different concentrations, drying them, and measuring the water potential at different water contents using the DPM. The resulting water potentials were compared to the reference potentials and differences were interpreted as the osmotic potential component. The DPM‐measured water potentials in drying soils can be significantly affected by osmotic potential, especially at higher matric potentials (low suctions). Two models accounting for ideal and one model accounting for non‐ideal electrolyte behaviour were used to compare osmotic potential predictions with measurements. At low to medium salt concentrations, all models performed fairly well. At high concentrations, only the model accounting for non‐ideal behaviour predicted the osmotic potential satisfactorily, whereas at very high concentrations, all models underestimated the impact of osmotic potential on water potential. This suggests that the surface properties of the soil matrix, such as the specific surface area and surface charges, may lead to a decrease in osmotic potential beyond what is expected in pure solutions.

Unveiling the tribological and corrosion characteristics of Ti20-Al16-V16-Fe16-Ni16-Cr16 high-entropy alloy developed via spark plasma sintering

This research explores the corrosion resistance and anti-wear property of near-equimolar Ti20-Al16-V16-Fe16-Ni16-Cr16 High Entropy Alloys (HEAs), fabricated at varying temperatures through spark plasma sintering (SPS) procedure. The alloy powders were processed and sintered at temperatures ranging from 700°C to 1100°C, and the resulting HEAs underwent comprehensive characterization. The tribological behavior of these sintered HEAs and their corrosion response in sulfuric and chloride environments were systematically investigated. Microstructural analyses were conducted before and after exposure to corrosive media using a scanning electron microscope. Notably, the assessments in both acid and salt media revealed that HEAs sintered at 1100°C exhibited the highest corrosion resistance, whereas those sintered at 700°C displayed the least resistance. The wear rate is improved by 130% over Inconel 718 alloy in the created HEA. This research signifies the potential of Ti20-Al16-V16-Fe16-Ni16-Cr16 HEA prepared through tailored SPS procedures, as corrosion and wear resistance alternatives surpass the performance of Ti6AlV4 and traditional alloys.

Characterization of methanogens from landfill samples: implications for sustainable biogas production

This case study aimed to isolate and identify methanogenic bacteria from landfill soil, mud, and leachate samples to assess their role in anaerobic digestion and biogas production. Anaerobic digestion involves the breakdown of organic matter by a diverse group of bacteria under oxygen-free conditions, resulting in the production of methane and carbon dioxide. The collected samples from the landfill were cultured in a modified mineral salt medium (MSM). Microscopic observations revealed distinct coccus and bacillus morphologies of the isolated methanogenic bacteria. Gas production experiments and substrate utilization studies identified two types of methanogens. Methanosarcina sp., which utilized acetate and methanol for methane production, and Methanobacterium sp., utilizing hydrogen and carbon dioxide, as well as acetate. Scanning electron microscope (SEM) analysis confirmed the different morphotypes of the isolated methanogens. The study findings demonstrated the presence of diverse methanogens in the landfill environment, contributing to anaerobic digestion and biogas production.

Lignin pyrolysis assisted by molten salt medium: Evolution behavior of volatiles and biochar structure

This study focuses on the use of a molten salt reaction medium (NaCl-KCl-LiCl) in the lignin pyrolysis process to modify the pyrolysis volatiles and biochar structure. The effect of pyrolysis reaction temperature (300°C, 400°C, 500°C, and 600°C) and lignin/molten salt mass ratios (3:1, 1:1, 1:3 and 1:5) on the evolution behavior of volatiles and biochar structure was explored. The pyrolysis products were determined using GS-MS, CO2 adsorption-desorption analyses, SEM, elemental analysis, proximate analysis, Raman, XRD, and TG/DTG analysis. Results indicated that the introduction of molten salt can enhance the lignin depolymerization, leading to the production of phenolic precursors. Moreover, the metal cation (Na+, K+ and Li+) of molten salt can in-situ induce the modification of biochar structure with high porosity. The lower sulfur content in biochar was attributed to the immobilize function of molten salt. The evolution behaviour of volatiles and biochar structure during molten salt-assisted lignin pyrolysis was proposed. This study can serve as a benchmark for the high-value recycling of industrial lignin waste.

Alternative plant protection using an indigenous bacterium (Stutzerimonas nitrititolerans) isolated from agricultural soil of potato fields in Western Algeria to biodegrade common pesticides

Nowadays, it is highly important to find ways to degrade pesticides residues from the environment. We studied degradation of carbamate, copper sulphate - Cymoxanil and Cycloxydim by using an indeginous bacterium Stutzerimonas nitrititolerans. This bacteria uses pesticides as source of carbon and solubilize them by their enzymatic machinery. Experiments were conducted using mineral salt medium (MSM) on agar supplemented with two different pesticides as sole carbon and energy source: carbamate and acetamiprid. These organic pesticides contain carbon (example of carbamate: NH2COOH). Growth of the bacteria could suggest that it has utilized the pesticide as its sole energy source, indicating its ability to degrade the pesticide. The effects of different factors on pesticides degradation were investigated such us pesticide tolerance. The bacteria were tested for the ability to tolerate high concentrations of pesticides to optimize the degradation conditions. The treatments consisted of carbon-free mineral salts medium (MSM) supplemented with pesticides that are usually used during cultivation of potato such as acetamiprid, carbamate, copper sulphate - Cymoxanil and Cycloxydim at increasing concentrations (70, 100, 200 and 500mgl-1). Bacterial growth was monitored by daily measurement of the optical density at 600 nm on UV-1600 Spectrophotometer. Only one strain (Labeled PF2 of Stutzerimonas nitrititolerans) showed potential to tolerate and mitigate the tested pesticides at high concentrations. Further, a phenotypic characterization was carried, and 16S rRNA gene sequencing analysis performed to identify the PF2 strain. Pesticides did not show any significant inhibitory effect on the isolate PF2. Comparison of sequences with GenBank database gave similarity with Stutzerimonas nitrititolerans with 99.74% of homology. A phylogenetic tree of Stutzerimonas nitrititolerans was constructed to show relationship to closely related bacteria. The potential and efficiency of the strain PF2 using pesticides can be considered as a qualitative leap in the field of pesticide bioremediation in agricultural soils.

Antibiofilm and wound healing efficacy of rhamnolipid biosurfactant against pathogenic bacterium Staphylococcus aureus

The present study evaluates the in-vitro antibiofilm activity against the biofilm formed by Staphylococcus aureus, and the wound-healing efficacy of two different types of rhamnolipids produced by Pseudomonas aeruginosa strain JS29 in S.aureus infected wounds. The biosurfactant production was carried out in a mineral salt medium supplemented with 2 % Glucose and 2 % Glycerol individually and thus were designated as RL-Glu and RL-Gly respectively. 0.5 mg/ml of RL-Glu and RL-Gly demonstrated 90 % growth inhibition of S. aureus while exhibiting bactericidal activity at 4 mg/ml of RL-Glu and 1 mg/ml of RL-Gly. Both types of rhamnolipid cause changes in membrane permeability leading to pathogens’ non-viability. 90 % inhibition of biofilm formation by S. aureus was observed at 2 mg/ml of RL-Glu and 0.5 mg/ml of RL-Gly, while 0.5 mg/ml of both rhamnolipid disrupted 90 % of the preformed biofilm. 0.5 mg/ml of RL-Glu and RL-Gly decreases the production of exopolysaccharides and also causes structural alteration. 0.5 mg/ml of RL-Glu and RL-Gly were found to exhibit effective wound healing efficacy in S. aureus infected wounds within 7 days of treatment. Histopathological studies of wound sites revealed efficient wound management by both the rhamnolipid. LCMS and GCMS characterization of the biosurfactant revealed that JS29 produces different rhamnolipid congeners when grown on different carbon sources, thereby influencing the antimicrobial, antibiofilm, and wound healing efficacy of rhamnolipid.

Coastal Almond-Leaved Pear (Pyrus spinosa) Seedlings’ Responses to Saline Stress Alleviated by Formulated L-Methionine and Bacterial Exogenous Soil Application

Coastal Pyrus spinosa seedlings were tested for their developmental, chlorophyll content and antioxidant performance under soil saline conditions where bacterial and l-methionine exogenous treatments were applied as potential saline alleviation stress schemes. Scaling up saline stress, the number of formed lateral shoots was reduced in all treatments. Medium salt stress (75 mM NaCl) demonstrated a rather unified decline in shoot fresh weight values, which became toxic at 100 mM NaCl, with up to 89.1% shoot fresh weight losses, in comparison to unchallenged status. Both exogenous applications increased root/shoot ratio, providing developmental boost for root growth. Total chlorophyll content values (May–July) did not differ among non-stressed plantlets independently of exogenous treatment. All experimental plantlet lines increased their antioxidant activity on scaled up soil NaCl enrichment. Νo differences in root orientation and their angle frequencies were observed while soil saline exposure took place. In brief, spring–summer exposure of P. spinosa plantlets under 100 mM NaCl saline stress can be manageable, achieving higher root/shoot ratio values, upregulating leaf antioxidant activity and optimizing root growth upon bacterial and l-methionine supplementation. However, many of the examined parameters were found to be not extensively different between exogenously treated plantlets and non-supplemented ones, suggesting a potential role of intergenerational and transgenerational stress memory.

Biodegradation of sulfamethoxazole by a bacterium isolated from the Hurricane overtop sediments

Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are commonly found in Louisiana's waterways, specifically in the waterways of Bayou Lafourche and the Intracoastal Canal. In August of 2021, Hurricane Ida flooded levees in Larose, Louisiana, where the bayou and canal intersect, and deposited sediment contaminated with industrial chemicals, antibiotics, and ARB. Many multidrug resistant bacteria were isolated from the sediments. One of the bacterial isolates, Alcaligenes faecalis, was able to use sulfamethoxazole (SMX) as its sole nitrogen source and was resistant at concentrations of 500 mg/L of SMX. The objective of this study was to find out the ability of this new isolate to degrade SMX. When this bacterium was grown on a basic mineral salt medium with SMX as the sole nitrogen source, 39.81 % SMX was removed in the culture, which was statistically significant compared to other treatment conditions. HPLC analysis showed the production of many metabolites. LC/MS confirmed the identity of two metabolites as 3-amino-5-methylisoxazole (3A-5M) and 3-hydroxy-5-methylisoxazole (3H-5M). A. faecalis hydrolyzed SMX to produce 3A-5M which was oxidatively deaminated further to yield 3H-5M with the release of ammonia. This reaction occurred only when there was no other nitrogen source other than SMX was present in the culture medium, which showed that this unique feature of the bacteria could be used to degrade SMX from the contaminated environment.

Enhancing the phytoremediation efficiency of Bacopa monnieri (L.) Wettst. using LED lights: a sustainable approach for heavy metal pollution control.

In this study, the impacts of LEDs on the phytoremediation of arsenic (As) and mercury (Hg) by Bacopa monnieri (L.) Wettst. were investigated, along with the examination of the biochemical characteristics of plants exposed to metal-induced toxicity. In vitro multiple and rapid plant propagations were successfully achieved by adding 1.0mg/L 6-Benzyl amino purine (BAP) to the Murashige and Skoog (MS) basal salt and vitamin culture medium. For plant-based remediation experiments, different concentrations of As (0-1.0mg/L) and Hg (0-0.2mg/L) were added to the water environment, and trials were conducted for four different application periods (1-21days). White, red, and blue LEDs, as well as white fluorescent light, were preferred as the light environment. The results revealed that LED lights were more effective for heavy metal accumulation, with red LED light significantly enhancing the plant's phytoremediation capacity compared to other LED applications. Moreover, when examining biochemical stress parameters such as levels of photosynthetic pigments, protein concentrations, and lipid peroxidation, plants under red LED light showed better results. Generally, the lowest results were obtained under white fluorescent light. These findings contribute to phytoremediation studies by highlighting the integration of LED lights, thereby enabling the development of a more effective, cost-efficient, and environmentally sustainable remediation system compared to other treatment methods.

Hot corrosion behavior of selective laser melted TiC/GT D222 nickel-based composite in 75% Na2SO4 and 25% K2SO4 molten salt medium at 900°C

PurposeThis paper aims to investigate the differences in hot corrosion behavior of the GTD222 superalloy and TiC/GTD222 composite in a mixed salt of 75% Na2SO4 and 25% K2SO4 at 900°C.Design/methodology/approachThe GTD222 superalloy and TiC/GTD222 nickel-based composite were prepared using selective laser melting (SLM). Subsequently, the hot corrosion behavior of the two alloys was systematically investigated in a salt mixture consisting of 75% Na2SO4 and 25% K2SO4 (Wt.%) at 900°C.FindingsThe TiC/GTD222 composite exhibited better hot corrosion resistance compared to the GTD222 superalloy. First, the addition of alloying elements led to the formation of a protective oxide film on the TiC/GTD222 composites 20 h before hot corrosion. Second, TiC/GTD222 composite corrosion surface has a higher Ti content, after 100 h of hot corrosion, the composite corrosion surface Ti content of 10.8% is more than two times the GTD222 alloy 4% Ti. The Ti and Cr oxides are tightly bonded, effectively resisting the erosion of corrosive elements.Originality/valueThe hot corrosion behavior of GTD222 superalloy and TiC/GTD222 composites prepared by SLM in a mixed salt of 75% Na2SO4 and 25% K2SO4 was studied for the first time. This study provides insights into the design of high-temperature alloys resistant to hot corrosion.

Hydrocarbon Degradation and Biodegraders in Oil Spillage Sites in Port Harcourt

Information on remediation of soils polluted from the activities of artisanal crude oil refining is lacking. The functional capability of the indigenous microbial community and prospects for recovery of important bio-resources has also not been explored. The aim of this study was to identify the hydrocarbon biodegrader present in oil spillage sites in Port Harcourt. Samples were taken from various sites (labelled ss1, ss2, ss3 and controls) in Port Harcourt and the samples were transported to the lab for bacteriological assessment. The samples were cultured in Nutrient agar and Basal Salt Medium (BSM). The total heterotrophic bacteria counts were enumerated by serially diluting the fluid sample. Microbial characterization was done based on morphological, physiological and biochemical tests. From the results, Pseudomonas species and Bacillus species were the probable isolated from the culture of hydrocarbon contaminated environment. The results also revealed increased compared to the control organism that maintained the same growth level throughout the 5 days of incubation, the isolated bacteria (Pseudomonas species and Bacillus species) had steady bacterial growth. This study has shown that Bacillus species and Pseudomonas aeroginosa are potential agents of bioremediation of environmental hydrocarbon pollution.

Polystyrene Microplastics Degradation by Microbial Consortium From Jakarta Bay

ABSTRACTThe continuously increasing accumulation of microplastics in the environment, such as polystyrene (PS), has posed an ecological and health threat. However, the information and biodegradation capability of plastics, including polystyrene, was still in the infancy stage in Indonesia. This study explored the potential of microbial consortia from Jakarta Bay to degrade polystyrene microplastics. The consortia were obtained from plastic waste with biofilms on their surfaces, collected from three stations in Jakarta Bay. The research enriched the biofilm's consortia using 1/10 Zobell marine broth media supplemented with 0.1% PS microplastics. Using enriched cultures, biodegradation tests were performed in a mineral salt medium with 0.2% PS microplastics as a sole carbon source for 60 days at 27°C, 120 rpm. Microbial consortia from Jakarta Bay showed an ability to perform polystyrene biodegradation. The calculated weight loss of the microplastics after 60 days of incubation was between 4% and 6.4%. The biodegradation of PS microplastics by the microbial consortium was also indicated by FTIR spectra, which showed changes in functional group transmittances and were confirmed by SEM data showing holes formation on PS surfaces. The results provide a baseline study for further research development in Indonesia's polystyrene biodegradation technology and management.

Indigo carmine biodegradation by endophytic Microbacterium zeae K5: Enzymatic insights, degradation mechanism, and ecotoxicity analysis

The enormous amount of colored effluent release from dying industries into fresh and marine reservoirs, causing ecotoxicity and serious health problems. Pertaining to this, the current research emphasis on the decolorization and degradation treatment of Indigo carmine (IC). The decolorization of IC with endophytic Microbacteium zeae K5, isolated from the root of the Salix purpurea plant was studied. In a minimal salt medium with shaking, full dye decolorization (400 mg/L) was achieved within a 24 h incubation period. During dye degradation, the activities of enzymes such as laccase (12.02 U/g), manganese peroxidase (4.23 U/g), and quinone dehydrogenase (0.09 U/g) were also observed. The biodegradation of IC into isatin sulfonic acid and isatin was confirmed by UV–VIS spectrophotometry and GC-MS analysis of dye samples extracted with ethyl acetate. Finally, phytotoxicity studies revealed that the IC degraded metabolites toxicity was lower than that of the parent dye compound. The current study demonstrated isolate M. zeae K5 has ability to efficiently break down IC, indicating its potential for future bioremediation uses.

Phase Separation and Aggregation of α-Synuclein Diverge at Different Salt Conditions.

The coacervation of alpha-synuclein (αSyn) into cytotoxic oligomers and amyloid fibrils are considered pathological hallmarks of Parkinson's disease. While aggregation is central to amyloid diseases, liquid-liquid phase separation (LLPS) and its interplay with aggregation have gained increasing interest. Previous work shows that factors promoting or inhibiting aggregation have similar effects on LLPS. This study provides a detailed scanning of a wide range of parameters, including protein, salt and crowding concentrations at multiple pH values, revealing different salt dependencies of aggregation and LLPS. The influence of salt on aggregation under crowding conditions follows a non-monotonic pattern, showing increased effects at medium salt concentrations. This behavior can be elucidated through a combination of electrostatic screening and salting-out effects on the intramolecular interactions between the N-terminal and C-terminal regions of αSyn. By contrast, this study finds a monotonic salt dependence of LLPS due to intermolecular interactions. Furthermore, it observes time evolution of the two distinct assembly states, with macroscopic fibrillar-like bundles initially forming at medium salt concentration but subsequently converting into droplets after prolonged incubation. The droplet state is therefore capable of inhibiting aggregation or even dissolving aggregates through heterotypic interactions, thus preventing αSyn from its dynamically arrested state.

Mycoremediation of Acetaminophen by the Fungi of Dothideomycetes sp. Isolate

Resources like air, water, and land are found to be contaminated by a broad variety of pharmaceutical contaminants. The release of industrial effluents, hospital wastewater, and untreated domestic water, which contains medications, colours, pharmaceutical blisters, and heavy metals that are ecotoxic even at concentrations of nanograms to micrograms, is a significant cause of water pollution. Mycoremediation is an operative approach is to detoxify these contaminants. The fungal strain was isolated from pharma industrial wastewater. Identification of the fungi was founded on the morphological and 18s rRNA sequencingtechnique. Isolate shared 99.82 % similarity with Zasmidium cellare and Cladosporium iridis strain CBS 138.40, suggesting the new species of fungi. The strain has received Gen bank accession number of OR081620.1. The fungal strain was found to degrade 85% of acetaminophen (1000 ppm) in 10 days when grown in mineral salt medium with acetaminophen as only carbon source. Glucose was found to enhance sporulation potential but not the degradative potential of the fungi. Identification of biodegradative metabolite was done by using thin layer chromatography, high performance liquid chromatography and liquid chromatography-mass spectroscopy. Mycodegradative metabolite of 4 Aminophenol was identified as acetaminophen.

Techno-economical valorization of sugarcane bagasse for efficiently producing optically pure D-(−)-lactate approaching the theoretical maximum yield in low-cost salt medium by metabolically engineered Klebsiella oxytoca

Sugarcane bagasse (SCB) was utilized for efficiently producing optically pure D-(−)-lactate by Klebsiella oxytoca KIS004-91T strain. Cellulase (15 U/g NaOH-treated SCB) sufficiently liberated high sugars with saccharifications of 79.8 % cellulose and 52.5 % hemicellulose. For separated hydrolysis and fermentation, D-(−)-lactate was produced at 53.5 ± 2.1 g/L (0.98 ± 0.01 g/g sugar utilized or 0.71 ± 0.01 g/g total sugars) while D-(−)-lactate at 47.2 ± 1.8 g/L (0.78 ± 0.03 g/g sugar used or 0.69 ± 0.01 g/g total sugars) was obtained under simultaneous saccharification and fermentation (SSF). D-(−)-lactate at 99.9 ± 0.9 g/L (0.97 ± 0.01 g/g sugar utilized or 0.78 ± 0.01 g/g total sugars) was improved via fed-batch SSF. Based on mass balance, raw SCB of 7 kg is required to produce 1 kg D-(−)-lactate. Unlike others, D-(−)-lactate production was performed in low-cost salt medium without requirements of rich nutrients. Costs regarding medium, purification, and waste disposal may be reduced. This unlocks economic capability of SCB bioconversion or agricultural and agro-industrial wastes into high valuable D-(−)-lactate.

Efficient photocatalytic H2O2 production and photodegradation of RhB over K-doped g-C3N4/ZnO S-scheme heterojunction

Designing efficient dual-functional catalysts for photocatalytic oxygen reduction to produce hydrogen peroxide (H2O2) and photodegradation of dye pollutants is challenging. In this work, we designed and fabricated an S-scheme heterojunction (g-C3N4/ZnO composite photocatalyst) via one-pot calcination of a mixture of ZIF-8 and melamine in the KCl/LiCl molten salt medium. The KCN/ZnO composite produced 4.72 mM of H2O2 within 90 min under illumination (with AM 1.5 filter), which is almost 1.3 and 7.8 times than that produced over KCN and ZnO, respectively. Simultaneously, the KCN/ZnO also showed excellent photodegradation performance for the dye pollutants (Rhodamine B, RhB), with a removal rate of 92 % within 2 h. The apparent degradation rate constant of RhB over KCN/ZnO was approximately 5–8 times that of KCN and ZnO. In the photocatalytic process, photo-generated holes and superoxide radicals are the main active species. Oxygen (O2) was mainly reduced to produce H2O2 via a two-electron (2e−) pathway with superoxide radicals as intermediates and the 2e− oxygen reduction reaction selectivity of KCN/ZnO was close to 69.82 %. Photo-generated holes are mainly responsible for the degradation of RhB. Compared with pure KCN and ZnO, the enhanced photocatalytic activity of the KCN/ZnO composite is mainly attributed to the following aspects: 1) larger specific surface area and pore volume is beneficial to expose more active sites; 2) stronger light harvesting ability and red-shifted absorption edge bestow the compound a stronger light utilization efficiency; 3) the construction of S-scheme heterostructure between KCN and ZnO improve the photogenerated electron-hole pairs separation ability and bestow photogenerated carriers a higher redox potential.

Isolation and Molecular Characterization of Polyester-Degrading Bacterial Strains from Municipal Wastewater and Their Application in Microplastic Degradation in Contaminated Wastewater

Diverse synthetic polymers find their regular application in routine life and are disposed of directly into the environment through various sources. The released microplastic and microfibres from the sources creates contamination in both aquatic and terrestrial environments. When these micropollutants enter the food chain, they have adverse effects on the environment and human health. This study focuses on the application of native bacterial strains isolated for the effective degradation of polyester microfibers. The isolated bacterial strains, namely MFB 6, MFB 8, and MFB 11, tolerant to polyethylene glycol (PEG), were identified as Bacillus sp., Paenibacillus sp., and Aeromonas veronii, respectively, with NCBI gene bank accession numbers ON318306, ON318390, and PP237260. Polyester biodegradation efficiency of 10.5%, 12.6% and 8.4% was achieved by MFB 6, MFB 8 and MFB 11, respectively, after 42 days of investigation in minimal salt medium under shake flask condition. In future the application of these microorganisms will help in sustainable management of synthetic microfiber pollutants and find their suitable application in micro plastic degradation in contaminated wastewater.

Screening of Different Fungi Strains Gongronella sp. WICC F60 and Cordyceps sp. WICC F61 for Degradation of Low-Density Polyethylene

Over the past decade, polyethylene (PE) products have become increasingly important in several industries. Their biggest concerns are plastic material degradation resistance and environmental longevity. Therefore, this study aims to find fungi that are capable of degrading low-density polyethylene (LDPE) efficiently. This study uses Gongronella sp. WICC F60, and Cordyceps sp., WICC F61. The fungi were grown on potato dextrose agar for 30 days. Following that, fungal colonies were placed in potato dextrose broth for incubation. The LDPE sample was then cultured with the fungal strain in a minimum salt medium with a 10% inoculum. After 30 days of biodegradation testing, the analysis was done. These studies measured LDPE sample weight loss, pH, and fungal biomass. It was observed that the LDPE sample weight loss increased with time until the end of inclubation. Gongronella sp. WICC F60 and Cordyceps sp. WICC F61 were able to degrade LDPE plastic. Both fungi show an increase in LDPE weight loss. However, Cordyceps sp. WICC F61 shows more efficiency in LDPE degradation compared to Gongronella sp. WICC F60. The LDPE weight loss using Gongronella sp. WICC F60 was 1.07%, which is lower than Gongronella sp. WICC F60's LDPE weight reduction of 5.56%.

In Silico Analysis and Validation of ymcA Gene of Bacillus Subtilis

This study aimed to analyze and validate the ymcA gene of Bacillus subtilis in silico. The bacterial strains used were B. subtilis 2049 (T) and B. subtilis HS, obtained from the National Center for Microbial Resource, Pune. The media used were LB medium and Mineral Salt Medium (MSM). The biofilm formation assay was performed in a microtiter plate, with each well inoculated with 980 µl of MSM and 20 µl of test cultures. The plate was incubated for 120 hrs at 37°C following phosphate buffer assay. The contents of the plate were removed by gently tapping at the bottom of the plate, rinsed with phosphate buffer saline, and de-stained using 70% ethanol for 15 min. The genomic DNA of B. subtilis 2049 (T) was extracted using the Chloroform: Isoamylalcohol method. The supernatant was taken in a sterile tube and stored at -80°C until further use.