Seed gum-based polysaccharides hydrogels for sustainable agriculture: A review.

Globally, water scarcity in arid and semiarid regions has become one of the critical issues that hinder sustainable agriculture. Agriculture, being a major water consumer, presents several challenges that affect water availability. Hydrogels derived from polysaccharides seed gums are hydrophilic polymers capable of retaining substantial moisture in their three-dimensional network and releasing it back into the soil during drought conditions. Implementation of hydrogels in the agricultural sectors enhances soil health, plant growth, and crop yield. Furthermore, the soil permeability, density, structure, texture, and rate of evaporation and percolation of water are modified by hydrogel. In this review, hydrogels based on natural plant seed gum like guar, fenugreek, Tara and locust beans have been discussed in terms of their occurrence, properties, chemical structure, method of synthesis, and swelling behavior. The focus extends to recent applications of modified seed gum-based natural hydrogels in agriculture, serving as soil conditioners and facilitating nutrient delivery to growing plants. The swelling behavior and inherent structure of these hydrogels can help researchers unravel their maximum possibilities to promote sustainable agriculture and attenuate the obstacles propounded by our dynamic nature. The current review also examines market growth, prospects, and challenges of eco-friendly hydrogels in recent times.

The potential of self-activated carbon for adsorptive removal of toxic phenoxyacetic acid herbicide from water.

Phenoxyacetic acid herbicides are widely used in agriculture for controlling weeds. These organic compounds are persistent and recalcitrant, often contaminating water and soil. Therefore, we studied five pristine biochars (BCs), and southern yellow pine (SYP) based self-activated carbon (SAC) for the adsorptive removal of 2,4-Dichlorophenoxyacetic acid (2,4-D) herbicide. Among the tested adsorbents, SYP-SAC-15 demonstrated higher (>90%) 2,4-D removal from water. The SYP-SAC-15 was produced using a facile and green route where the biomass pyrolysis gases worked as activating agents creating a highly porous structure with a surface area of 1499.79 m2/g. Different adsorption kinetics and isotherm models were assessed for 2,4-D adsorption on SYP-SAC-15, where the data fitted best to pseudo-second order (R2 > 0.999) and Langmuir (R2 > 0.991) models, respectively. Consequently, the adsorption process was mainly dominated by the chemisorption mechanism with monolayer coverage of SYP-SAC-15 surface with 2,4-D molecules. At the optimum pH of 2, the maximum 2,4-D adsorption capacity of SYP-SAC-15 reached 471.70 mg/g. Furthermore, an increase in the water salinity demonstrated a positive influence on 2,4-D adsorption, whereas humic acid (HA) showed a negative impact on 2,4-D adsorption. The regeneration ability of SYP-SAC-15 showed excellent performance by retaining 71.09% adsorption capability at the seventh adsorption-desorption cycle. Based on the operating pH, surface area, spectroscopic data, kinetics, and isotherm modeling, the adsorption mechanism was speculated. The 2,4-D adsorption on SYP-SAC-15 was mainly governed by pore filling, electrostatic interactions, hydrogen bonding, hydrophobic and π-π interactions.

Algal biochar mediated detoxification of plant biomass hydrolysate: Mechanism study and valorization into polyhydroxyalkanoates.

In this study, fourteen types of biochar produced using seven biomasses at temperatures 300 °C and 600 °C were screened for phenolics (furfural and hydroxymethylfurfural (HMF)) removal. Eucheuma spinosum biochar (EB-BC 600) showed higher adsorption capacity to furfural (258.94 ± 3.2 mg/g) and HMF (222.81 ± 2.3 mg/g). Adsorption kinetics and isotherm experiments interpreted that EB-BC 600 biochar followed the pseudo-first-order kinetic and Langmuir isotherm model for both furfural and HMF adsorption. Different hydrolysates were detoxified using EB-BC 600 biochar and used as feedstock for engineered Escherichia coli. An increased polyhydroxyalkanoates (PHA) production with detoxified barley biomass hydrolysate (DBBH: 1.71 ± 0.07 g PHA/L), detoxified miscanthus biomass hydrolysate (DMBH: 0.87 ± 0.03 g PHA/L) and detoxified pine biomass hydrolysate (DPBH: 1.28 ± 0.03 g PHA/L) was recorded, which was 2.8, 6.4 and 3.4 folds high as compared to undetoxified hydrolysates. This study reports the mechanism involved in furfural and HMF removal using biochar and valorization of hydrolysate into PHA.

Enhancement of polyhydroxybutyrate production by introduction of heterologous phasin combination in Escherichia coli.

Phasin is a surface-binding protein of polyhydroxyalkanoate (PHA) granules that is encoded by the phaP gene. As its expression increases, PHA granules become smaller, to increase their surface area, and are densely packed inside the cell, thereby increasing the PHA content. A wide range of PHA-producing bacteria have phaP genes; however, their PHA productivity differs, although they are derived from the cognate bacterial host cell. Modulating phasin expression could be a new strategy to enhance PHA production. This study aimed to characterize the effect of heterologous phasins on the reconstitution of E. coli BL21(DE3) and determine the best synergistic phaP gene combination to produce polyhydroxybutyrate (PHB). We identified novel phasins from a PHB high-producer strain, Halomonas sp. YLGW01, and introduced a combination of phaP genes into Escherichia coli. The resulting E. coli phaP1,3 strain had enhanced PHB production by 2.9-fold, leading to increased cell mass and increased PHB content from 48 % to 65 %. This strain also showed increased tolerance to inhibitors, such as furfural and vanillin, enabling the utilization of lignocellulose biosugar as a carbon source. These results suggested that the combination of phaP1 and phaP3 genes from H. sp. YLGW01 could increase PHB production and robustness.

Controlling catabolite repression for isobutanol production using glucose and xylose by overexpressing the xylose regulator.

Using lignocellulosic biomass is immensely beneficial for the economical production of biochemicals. However, utilizing mixed sugars from lignocellulosic biomass is challenging because of bacterial preference for specific sugar such as glucose. Although previous studies have attempted to overcome this challenge, no studies have been reported on isobutanol production from mixed sugars in the Escherichia coli strain. To overcome catabolite repression of xylose and produce isobutanol using mixed sugars, we applied the combination of three strategies: (1) deletion of the gene for the glucose-specific transporter of the phosphotransferase system (ptsG); (2) overexpression of glucose kinase (glk) and glucose facilitator protein (glf); and (3) overexpression of the xylose regulator (xylR). xylR gene overexpression resulted in 100% of glucose and 82.5% of xylose consumption in the glucose-xylose mixture (1:1). Moreover, isobutanol production increased by 192% in the 1:1 medium, equivalent to the amount of isobutanol produced using only glucose. These results indicate the effectiveness of xylR overexpression in isobutanol production. Our findings demonstrated various strategies to overcome catabolite repression for a specific product, isobutanol. The present study suggests that the selected strategy in E. coli could overcome the major challenge using lignocellulosic biomass to produce isobutanol.

Enhanced tolerance of Cupriavidus necator NCIMB 11599 to lignocellulosic derived inhibitors by inserting NAD salvage pathway genes.

Polyhydroxybutyrate (PHB) is a bio-based, biodegradable and biocompatible plastic that has the potential to replace petroleum-based plastics. Lignocellulosic biomass is a promising feedstock for industrial fermentation to produce bioproducts such as polyhydroxybutyrate (PHB). However, the pretreatment processes of lignocellulosic biomass lead to the generation of toxic byproducts, such as furfural, 5-HMF, vanillin, and acetate, which affect microbial growth and productivity. In this study, to reduce furfural toxicity during PHB production from lignocellulosic hydrolysates, we genetically engineered Cupriavidus necator NCIMB 11599, by inserting the nicotine amide salvage pathway genes pncB and nadE to increase the NAD(P)H pool. We found that the expression of pncB was the most effective in improving tolerance to inhibitors, cell growth, PHB production and sugar consumption rate. In addition, the engineered strain harboring pncB showed higher PHB production using lignocellulosic hydrolysates than the wild-type strain. Therefore, the application of NAD salvage pathway genes improves the tolerance of Cupriavidus necator to lignocellulosic-derived inhibitors and should be used to optimize PHB production.

Coproduction of exopolysaccharide and polyhydroxyalkanoates from Sphingobium yanoikuyae BBL01 using biochar pretreated plant biomass hydrolysate.

Sphingobium yanoikuyae BBL01 can produce exopolysaccharides (EPS) and polyhydroxyalkanoates (PHAs). The effect of side products (furfural, hydroxymethylfurfural (HMF), vanillin, and acetate) produced during pretreatment of biomass was evaluated on S. yanoikuyae BBL01. It was observed that a certain concentration range (0.01-0.03 %) of these compounds can improve growth, EPS production, and polyhydroxybutyrate (PHB) accumulation. The addition of HMF increases glucose and xylose utilization while other side products have a negative effect. The C/N of 5 favors EPS production (3.24 ± 0.05 g/L), while a higher C/N ratio of 30 promotes PHB accumulation (38.7 ± 0.08 % w/w), when commercial sugar is used as a carbon source. Pine biomass-derived biochar was able to remove 40 ± 2.1 % of total phenolic. Various biomass hydrolysates were evaluated and the use of detoxified pine biomass hydrolysate (DPH) as a carbon source resulted in the higher coproduction of EPS (2.83 ± 0.03 g/L) and PHB (40.8 ± 2.4 % w/w).

Simultaneous monitoring of each component on degradation of blended bioplastic using gas chromatography-mass spectrometry.

The increasing interest in bioplastics, with regard to future environmental issues, has rendered research on bioplastic biodegradation highly important. However, only a few tools directly monitor the degradation of bioplastics without measuring the levels of gaseous products, such as carbon dioxide. Classical nonquantitative methods, such as clear zone tests on solid plates, and less-sensitive weight-loss experiments in liquid media measured using a precision scale, are still employed to screen the microbial players associated with bioplastic degradation and monitor the biodegradation rates. However, the simultaneous monitoring of the degradation of each component of blended bioplastics has not been previously reported. In the present study, to provide information regarding the degradation rates and compositional changes of different bioplastics in a blend in a time-dependent manner, we simultaneously monitored and quantified the degradation of four bioplastics, polyhydroxybutyrate (PHB), polybutylene succinate (PBS), polycaprolactone (PCL), and poly(butylene adipate-co-terephthalate) (PBAT), by Bacillus sp. JY36 using gas chromatography-mass spectrometry (GC-MS) analysis after fatty acid methyl ester (FAME) derivatization. Our results demonstrate the feasibility of using the GC-MS-based method described here to obtain comprehensive data regarding blended bioplastics and their degradation. Moreover, our findings indicate that this method may support classical analytic tools for assessing bioplastic biodegradation.

Lignocellulosic hydrolysate based biorefinery for marine exopolysaccharide production and application of the produced biopolymer in environmental clean-up.

The present study deals with the utilization of lignocellulosic hydrolysate-based carbon source for exopolysaccharide (EPS) production using newly reported marine Echinicola sediminis BBL-M-12. This bacterium produced 7.56 g L-1 and 5.32 g L-1 of EPS on supplementing 30 g L-1 glucose and 10 g L-1 xylose as the sole carbon source, respectively. Whereas on feeding Miscanthus hydrolysate (MCH) with glucose content adjusting to 20 g L-1, E. sediminis BBL-M-12 produced 6.18 g L-1 of EPS. The inhibitors study showed bacterium could tolerate higher concentrations of fermentation inhibitors include furfural (0.05%), 5-hydroxymethylfurfural (0.1%), vanillin (0.1%) and acetate (0.5%). Moreover, the EPS composition was greatly altered with the type and concentration of carbon source supplied, although ß-D-Glucopyranose, ß-D-Galactopyranose, and ß-D-Xylopyranose were the dominant monomers detected. Interestingly, E. sediminis BBL-M-12 EPS revealed excellent environmental applications like clay flocculation, oil emulsification, and removal of humic acid, textile dye, and heavy metal from the aqueous phase.

Advances in algal biomass pretreatment and its valorisation into biochemical and bioenergy by the microbial processes.

Urbanization and pollution are the major issues of the current time own to the exhaustive consumption of fossil fuels which have a detrimental effect on the nation's economies and air quality due to greenhouse gas (GHG) emissions and shortage of energy reserves. Algae, an autotrophic organism provides a green substitute for energy as well as commercial products. Algal extracts become an efficient source for bioactive compounds having anti-microbial, anti-oxidative, anti-inflammatory, and anti-cancerous potential. Besides the conventional approach, residual biomass from any algal-based process might act as a renewable substrate for fermentation. Likewise, lignocellulosic biomass, algal biomass can also be processed for sugar recovery by different pre-treatment strategies like acid and alkali hydrolysis, microwave, ionic liquid, and ammonia fiber explosion, etc. Residual algal biomass hydrolysate can be used as a feedstock to produce bioenergy (biohydrogen, biogas, methane) and biochemicals (organic acids, polyhydroxyalkanoates) via microbial fermentation.

Finding of novel polyhydroxybutyrate producer Loktanella sp. SM43 capable of balanced utilization of glucose and xylose from lignocellulosic biomass.

Polyhydroxybutyrate (PHB) is a potential substitute for plastics derived from fossil fuels, owing to its biodegradable and biocompatible properties. Lignocellulosic biomass could be used to reduce PHB production costs; however, the co-utilization of sugars, such as glucose and xylose, without catabolite repression is a difficult problem to be solved. Here, we selected a novel Loktanella sp. SM43 from a marine environment and optimized the conditions for PHB production. Loktanella sp. SM43 showed high PHB production (66.5% content) from glucose. When glucose and xylose were used together, this strain showed high utilization of both substrates compared to other high PHB-producers such as Halomonas sp. and Cupriavidus necator, which showed glucose preference. Loktanella sp. SM43 showed high growth and PHB production with lignocellulosic hydrolysates. When pine tree hydrolysates were used, PHB production was the highest at 3.66 ± 0.01 g/L, followed by Miscanthus (3.46 ± 0.09 g/L) and barley straw hydrolysate (3.36 ± 0.36 g/L). Overall, these results reveal the potential of Loktanella sp. SM43 to produce PHB using various lignocellulosic hydrolysates as feedstock and the first systematic study for PHB production with Loktanella sp. The approach of screening novel strains is a strategy to overcome co-utilization of sugars without genetic engineering.

Novel Poly(butylene adipate-co-terephthalate)-degrading Bacillus sp. JY35 from wastewater sludge and its broad degradation of various bioplastics.

Poly(butylene adipate-co-terephthalate) (PBAT), a bioplastic consisting of aliphatic hydrocarbons and aromatic hydrocarbons, was developed to overcome the shortcomings of aliphatic and aromatic polyesters. Many studies report the use of PBAT as a blending material for improving properties of other bioplastics. However, there are few studies on microorganisms that degrade PBAT. We found six kinds of PBAT-degrading microorganisms from various soils. Among these, Bacillus sp. JY35 showed superior PBAT degradability and robustness to temperature. We monitored the degradation of PBAT films by Bacillus sp. JY35 using scanning electron microscopy, field emission scanning electron microscopy, Fourier-transform infrared spectroscopy, and gel permeation chromatography. GC-MS was used to measure the PBAT film degradation rate at different temperatures and with additional NaCl and carbon sources. Certain additional carbon sources improve the growth of Bacillus sp. JY35. However, this did not increase PBAT film degradation. Time-dependent PBAT film degradation rates were measured during three weeks of cultivation, after which the strain achieved almost 50% degradation. Additionally, various bioplastics were applied to solid cultures to confirm the biodegradation range of Bacillus sp. JY35, which can degrade not only PBAT but also PBS, PCL, PLA, PHB, P(3HB-co-4HB), P(3HB-co-3HV), P(3HB-co-3HHx), and P(3HB-co-3HV-co-3HHx), suggesting its usability as a superior bioplastic degrader.

Progress in microalgal mediated bioremediation systems for the removal of antibiotics and pharmaceuticals from wastewater.

Worldwide demand for antibiotics and pharmaceutical products is continuously increasing for the control of disease and improvement of human health. Poor management and partial metabolism of these compounds result in the pollution of aquatic systems, leading to hazardous effects on flora, fauna, and ecosystems. In the past decade, the importance of microalgae in micropollutant removal has been widely reported. Microalgal systems are advantageous as their cultivation does not require additional nutrients: they can recover resources from wastewater and degrade antibiotics and pharmaceutical pollutants simultaneously. Bioadsorption, degradation, and accumulation are the main mechanisms involved in pollutant removal by microalgae. Integration of microalgae-mediated pollutant removal with other technologies, such as biodiesel, biochemical, and bioelectricity production, can make this technology more economical and efficient. This article summarizes the current scenario of antibiotic and pharmaceutical removal from wastewater using microalgae-mediated technologies.

Adsorptive removal of synthetic plastic components bisphenol-A and solvent black-3 dye from single and binary solutions using pristine pinecone biochar.

The existing study deals with adsorptive removal of the endocrine-disrupting chemical bisphenol-A and toxic azo dye solvent black-3 from single and binary solutions. These two chemicals are commonly used as an additive in the synthetic plastic industries. Among the tested twenty pristine and modified biochars, the pristine pinecone biochar produced at 750 °C revealed greater bisphenol-A removal. Simulation of the experimental data obtained for bisphenol-A and dye removal from the single-component solution offered a best-fit to Elovich (R2 > 0.98) and pseudo-second-order (R2 > 0.99) kinetic models, respectively. Whereas for the bisphenol-A + dye removal from binary solution, the values for bisphenol-A adsorption were best suited to Elovich (R2 > 0.98), while pseudo-second-order (R2 > 0.99) for dye removal. Similarly, the two-compartment model also demonstrated better values (R2 > 0.92) for bisphenol-A and dye removal from single and binary solutions with greater Ffast values (except for bisphenol-A in binary solution). The Langmuir isotherm model demonstrated the highest regression coefficient values (R2 > 0.99) for bisphenol-A and dye removal with the highest adsorption capacity of 38.387 mg g-1 and 346.856 mg g-1, correspondingly. Besides, the co-existence of humic acid revealed a positive impact on bisphenol-A removal, while the dye removal rate was slightly hindered in presence of humic acid. The absorption process showed monolayer coverage of biochar surface with contaminants using a chemisorption mechanism with fast reactions between functional groups on the adsorbate and adsorbent. Whereas the adsorption mechanism was primarily controlled by hydrogen bonding, hydrophobic and π-π electron-donor-acceptor interactions as confirmed by FTIR, XPS, and pH investigations.

Finding of novel lactate utilizing Bacillus sp. YHY22 and its evaluation for polyhydroxybutyrate (PHB) production.

Polyhydroxyalkanoates (PHAs) and their derivatives are biopolymers that have the potential of replacing petroleum-based plastics and can be produced and degraded via bacterial metabolism. However, there are only a few studies on polyhydroxybutyrate (PHB) production using lactate, one of the major waste organic acids that could be implemented in the production of polylactic acid (PLA). Herein, we screened and characterized the PHA-producing microbial strains isolated from saltern soil from Docho Island (South Korea). Among the 24 identified microorganisms that can use lactate as a carbon source, Bacillus sp. YHY22, a newly reported strain, produced the highest amount of PHB: 4.05 g/L with 6.25 g/L dry cell weight, which is 64.7% PHB content under optimal production conditions. Bacillus sp. YHY22 could form the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer with propionate addition. Moreover, Bacillus sp. YHY22 produced PHB in non-sterilized 2% lactate and 8% NaCl marine broth culture medium, suggesting that its production can occur in high salinity media without additional sterilization steps, rendering fermentation cost- and time-efficient.

Gamma aminobutyric acid (GABA) production in Escherichia coli with pyridoxal kinase (pdxY) based regeneration system.

Gamma-aminobutyric acid (GABA) is a non-proteinogenic amino acid act as a major neurotransmitter inhibitor in the nervous system of mammals. It also used as a precursor of bioplastics synthesis such as N-methylpyrolidone and polyamide 4. Chemical-based synthesis methods have many environmental-related issues, so efforts have been made to develop biosynthetic methods to produce GABA. Glutamate decarboxylase (GAD) transforms L-glutamate to GABA using pyridoxal 5'-phosphate (PLP) as a cofactor. Bioconversion of GABA with whole cells overexpressing the glutamate decarboxylase has advantages of fewer byproducts and rapid reaction. However, there is a bottleneck in the whole-cell bioconversion system i.e., higher GABA production require a large amount of cofactor PLP which make the process costly. Therefore, pyridoxal kinase (PdxY) able to regenerate PLP was introduced in the whole-cell system to construct a new GABA producing system. Culture and reaction conditions were optimized, and 100% conversion of 0.6 M MSG was obtained. This study reports that a competitive level of GABA production could be achieved without supplying additional PLPs.

Novel Polyhydroxybutyrate-Degrading Activity of the Microbulbifer Genus as Confirmed by Microbulbifer sp. SOL03 from the Marine Environment.

Ever since bioplastics were globally introduced to a wide range of industries, the disposal of used products made with bioplastics has become an issue inseparable from their application. Unlike petroleum-based plastics, bioplastics can be completely decomposed into water and carbon dioxide by microorganisms in a relatively short time, which is an advantage. However, there is little information on the specific degraders and accelerating factors for biodegradation. To elucidate a new strain for biodegrading poly-3-hydroxybutyrate (PHB), we screened out one PHB-degrading bacterium, Microbulbifer sp. SOL03, which is the first reported strain from the Microbulbifer genus to show PHB degradation activity, although Microbulbifer species are known to be complex carbohydrate degraders found in high-salt environments. In this study, we evaluated its biodegradability using solid- and liquid-based methods in addition to examining the changes in physical properties throughout the biodegradation process. Furthermore, we established the optimal conditions for biodegradation with respect to temperature, salt concentration, and additional carbon and nitrogen sources; accordingly, a temperature of 37°C with the addition of 3% NaCl without additional carbon sources, was determined to be optimal. In summary, we found that Microbulbifer sp. SOL03 showed a PHB degradation yield of almost 97% after 10 days. To the best of our knowledge, this is the first study to investigate the potent bioplastic degradation activity of Microbulbifer sp., and we believe that it can contribute to the development of bioplastics from application to disposal.

Isolation of Microbulbifer sp. SOL66 with High Polyhydroxyalkanoate-Degrading Activity from the Marine Environment.

Having the advantage of eco-friendly decomposition, bioplastics could be used to replace petroleum-based plastics. In particular, poly(3-hydroxybutyrate) (PHB) is one of the most commercialized bioplastics, however, necessitating the introduction of PHB-degrading bacteria for its effective disposal. In this study, Microbulbifer sp. SOL66 (94.18% 16S rRNA with similarity to Microbulbifer hydrolyticus) demonstrated the highest degradation activity among five newly screened Microbulbifer genus strains. Microbulbifer sp. SOL66 showed a rapid degradation yield, reaching 98% in 4 days, as monitored by laboratory scale, gas chromatography-mass spectrometry, scanning electron microscopy, gel permeation chromatography, and Fourier transform infrared spectroscopy. The PHB film was completely degraded within 7 days at 37 °C in the presence of 3% NaCl. When 1% xylose and 0.4% ammonium sulfate were added, the degradation activity increased by 17% and 24%, respectively. In addition, this strain showed biodegradability on pellets of poly(3-hydroxybutyrate-co-4-hydroxybutyrate), as confirmed by weight loss and physical property changes. We confirmed that Microbulbifer sp. SOL66 has a great ability to degrade PHB, and has rarely been reported to date.

Novel phasins from the Arctic Pseudomonas sp. B14-6 enhance the production of polyhydroxybutyrate and increase inhibitor tolerance.

Phasin (PhaP), one of the polyhydroxyalkanoate granule-associated protein, enhances cell growth and polyhydroxybutyrate (PHB) biosynthesis by regulating the number and size of PHB granules. However, few studies have applied phasins to various PHB production conditions. In this study, we identified novel phasin genes from the genomic data of Arctic soil bacterium Pseudomonas sp. B14-6 and determined the role of phaP1Ps under different PHB production conditions. Transmission electron microscopy and gel permeation chromatography revealed small PHB granules with high-molecular weight, while differential scanning calorimetry showed that the extracted PHB films had similar thermal properties. The phasin protein derived from Pseudomonas sp. B14-6 revealed higher PHB production and exhibited higher tolerance to several lignocellulosic biosugar-based inhibitors than the phasin protein of Ralstonia eutropha H16 in a recombinant Escherichia coli strain. The increased tolerance to propionate, temperature, and other inhibitors was attributed to the introduction of phaP1Ps, which increased PHB production from lignocellulosic hydrolysate (2.39-fold) in the phaP1Ps strain. However, a combination of phasin proteins isolated from two different sources did not increase PHB production. These findings suggest that phasin could serve as a powerful means to increase robustness and PHB production in heterologous strains.

Polyhydroxyalkanoates (PHAs) degradation by the newly isolated marine Bacillus sp. JY14.

Polyhydroxyalkanoates (PHAs) are bioplastic substitutes for petroleum-derived plastics that may help to reduce the increasing environmental impact of plastic pollution. Among them, polyhydroxybutyrate (PHB) is a promising biopolymer, incentivizing many researchers to search for PHB-producing and PHB-degrading bacteria for improved PHB utilization. Many novel PHB-producing microorganisms have been discovered; however, relatively few PHB-degrading bacteria have been identified. Six PHB-degrading bacteria were found in marine soil and investigated their PHB-degrading abilities under various temperature and salinity conditions using solid-media based culture. Finally, thermotolerant and halotolerant PHB-degrader Bacillus sp. JY14 was selected. PHB degradation was confirmed by monitoring changes in the physical and chemical properties of PHB films incubated with Bacillus sp. JY14 using scanning electron microscopy, Fourier-transform infrared spectroscopy, and gel permeation chromatography. Further, PHB degradation ability of Bacillus sp. JY14 was measured in liquid culture by gas chromatography. After 14 days of cultivation with PHB film, Bacillus sp. JY14 achieved approximately 98% PHB degradation. Applying various bioplastics to assess the bacteria's biodegradation capabilities, the result showed that Bacillus sp. JY14 could also degrade P(3HB-co-4HB) and P(3HB-co-3HV). Overall, this study identified a thermotolerant and halotolerant bacteria capable of PHB degradation under solid and liquid conditions. These results suggest that this bacteria could be utilized to degrade various PHAs.