Optimum Growth Temperature Research Articles

Biological Characteristics, Pathogenicity, and Sensitivity to Fungicides of Four Species of Lasiodiplodia on Avocado Fruits

This study focuses on four species of Lasiodiplodia (L. euphorbiaceicola, L. mahajangana, L. theobromae, and L. pseudotheobromae), which are associated with avocado stem end rot (SER) in Hainan, China. The factors affecting the growth of Lasiodiplodia, pathogenicity to avocado and other tropical fruits, and sensitivity to 12 fungicides, were tested. All Lasiodiplodia spp. isolates were grown between 10 °C and 40 °C, with optimal growth temperature ranging from 28 to 30 °C; the lethal temperature ranged from 51 to 53 °C for 10 min. Optimal growth pH ranged from 5 to 6. The most suitable medium was PDA, the preferred carbon sources were D–fructose and soluble starch, and the preferred nitrogen sources were yeast and beef extract. All Lasiodiplodia spp. isolates were highly pathogenic to avocado fruit. In addition, their pathogenicity to six tropical fruits (banana guava, mango, papaya, pitaya, and soursop) was evaluated, and the results reveal that all four species of Lasiodiplodia are able to infect these fruits to various degrees of severity. The pathogenicity of both L. theobromae and L. pseudotheobromae was the highest among all the species tested. All Lasiodiplodia spp. isolates were highly susceptible to the fungicides fludioxonil, carbendazim, thiophanate–methyl, tetramycin, iprodione, tebuconazole, prochloraz, and imazalil, which are good candidates for controlling avocado SER. The results of the present study provide important information on the biological characteristics of these four species of Lasiodiplodia and provide a basis for the management of SER in avocado.

Etiology of Pine Ghost Canker in Southern California Urban Forests.

Pine ghost canker is a recently described disease affecting multiple pine species in urban forests of Southern California. Symptoms include wedged cankers with irregular margins and cryptic discoloration on cross-sections of branches, which can lead to severe dieback and potentially tree death. In this study, we identified and characterized five Neofusicoccum species (N. luteum, N. mediterraneum, N. parvum, N. stellenboschianum, and N. vitifusiforme) as the primary etiological agents of pine ghost canker. These pathogens were consistently isolated from multiple symptomatic pine samples (n = 41) and identified by morphology and phylogenetic analyses using four DNA barcodes (rDNA ITS, tef1, tub2, and rpb2). Pathogenicity was confirmed on healthy branches of 15-year-old Monterey pines, where the five Neofusicoccum species, caused vascular lesions that were not significantly different in length. Secondary fungi (Diaporthe, Diplodia, Neopestalotiopsis, and Pestalotiopsis spp.) were also recovered from symptomatic tissues but did not cause vascular lesions in pathogenicity tests. The optimal temperature for mycelial growth of N. luteum and N. parvum was 30 °C, whereas for N. mediterraneum, N. stellenboschianum and N. vitifusiforme, it was 25 °C. All five species were able to resume growth at room temperature (20 °C) after showing no growth during a 7-day exposure to 5 °C and 40 °C. This study constitutes the first report of N. luteum, N. stellenboschianum, and N. vitifusiforme causing pine ghost canker in California. Environmental factors such as warmer temperatures, irrigation, and pest infestations are discussed as drivers of disease expression in pine trees. Management practices are also proposed.

Optimizing fungicide application timing for spring dead spot based on soil temperature and season

AbstractSpring dead spot (SDS) (Ophiosphaerella spp.) is the most detrimental disease to warm‐season turfgrasses in areas with cold‐induced dormancy. Fungicide applications do not provide consistent SDS suppression. One reason for this inconsistency is the use of solely calendar‐based fungicide applications instead of considering both calendar date and soil temperature. A field study was conducted at three separate hybrid bermudagrass (Cynodon dactylon (L.) Pers. × transvaalensis Burtt Davy) locations in Virginia to determine the optimal soil temperature and timing for SDS suppression with tebuconazole and isofetamid. Tebuconazole (1.5 kg a.i. ha−1) and isofetamid (4.1 kg a.i. ha−1) were applied at 11 different timings throughout the year based on soil temperatures at a 0‐ to 10‐cm depth. Plots were assessed for SDS severity in the spring and early summer of 2021 and 2022. Two in vitro studies were also conducted with Ophiosphaerella herpotricha and Ophiosphaerella korrae isolates to (1) determine the optimal temperature for growth on potato dextrose agar (PDA) placed on a thermogradient table (13–33°C) and (2) compare the daily growth rate of O. herpotricha and O. korrae isolates at 11, 19, and 27.5°C on PDA. In the field study, isofetamid suppressed SDS more than tebuconazole. Fall applications when soil temperatures were 13°C consistently provided the best SDS suppression. For the in vitro studies, both species grew optimally between 24 and 25°C, yet O. korrae and O. herpotricha growth rates differed at 11°C.

Promises and challenges in inferring the evolution of ancient organisms using optimum growth temperature

Promises and challenges in inferring the evolution of ancient organisms using optimum growth temperature

Caracterización fenotípica y simbiótica de las bacterias que nodulan Genista saharae en la región árida de Argelia

Twenty bacterial strains had been isolated from root nodules of Genista saharae that grew wild in Biskra and El Oued city (Northeastern Algerian Sahara). This study focused on obtaining isolates of legume nodule bacteria (LNB) from the plant G. saharae and evaluated their effectiveness in forming a symbiotic relationship with the legume species Vigna unguiculata through cross-inoculation. Additionally, the study aimed to identify the successful cross-inoculation group of LNB strains based on their phenotypic characteristics. The growth capacity of isolates under varying salinity conditions [NaCl] and pH levels was investigated using a spectrophotometer (96-microplate reader). The API 20NE and API 20E systems were used to identify the biochemical characteristics of the isolates. In addition, the rhizospheric soil samples from the two study sites were analyzed using standard analytical techniques of soil. All isolates established effective symbioses with Vigna unguiculata, were Gram-negative rods, and were fast-growing. The optimal growth temperature was between 28 °C and 37 °C; some isolates were thermophiles and specifically withstood extreme heat between 45-50 °C. Furthermore, they demonstrated a wide tolerance range to pH (5–10) with salt tolerance ranging from 100 mM to 500 mM. Biochemical results revealed that the isolates assimilated various sources of carbon and nitrogen and displayed numerous enzyme activities. Physicochemical analysis revealed that all the soils were deficient in nutrients and had an alkaline pH. This study enabled us to identify the effective stress-tolerant strains, which could be used in the future to inoculate plants for environmental applications. Keywords: Rhizobia, morpho-physiological and biochemical characterization.

The characterization of ancient Methanococcales malate dehydrogenases reveals that strong thermal stability prevents unfolding under intense γ-irradiation.

Malate dehydrogenases (MalDH) (EC.1.1.1.37), which are involved in the conversion of oxaloacetate to pyruvate in the tricarboxylic acid cycle, are a relevant model for the study of enzyme evolution and adaptation. Likewise, a recent study showed that Methanococcales, a major lineage of Archaea, is a good model to study the molecular processes of proteome thermoadaptation in prokaryotes. Here, we use ancestral sequence reconstruction and paleoenzymology to characterize both ancient and extant MalDHs. We observe a good correlation between inferred optimal growth temperatures (OGTs) and experimental optimal temperatures for activity (A-Topt). In particular, we show that the MalDH present in the ancestor of Methanococcales was hyperthermostable and had an A-Topt of 80°C, consistent with a hyperthermophilic lifestyle. This ancestor gave rise to two lineages with different thermal constraints, one remaining hyperthermophilic while the other underwent several independent adaptations to colder environments. Surprisingly, the enzymes of the first lineage have retained a thermoresistant behavior (i.e., strong thermostability and high A-Topt), whereas the ancestor of the second lineage shows a strong thermostability, but a reduced A-Topt. Using mutants, we mimic the adaptation trajectory towards mesophily and show that it is possible to significantly reduce the A-Topt without altering the thermostability of the enzyme by introducing a few mutations. Finally, we reveal an unexpected link between thermostability and the ability to resist γ-irradiation-induced unfolding.

Simultaneous saccharification and fermentation for d-lactic acid production using a metabolically engineered Escherichia coli adapted to high temperature

BackgroundEscherichia coli JU15 is a metabolically engineered strain capable to metabolize C5 and C6 sugars with a high yield of d-lactic acid production at its optimal growth temperature (37 °C). The simultaneous saccharification and fermentation process allow to use lignocellulosic biomass as a cost-effective and high-yield strategy. However, this process requires microorganisms capable of growth at a temperature close to 50 °C, at which the activity of cellulolytic enzymes works efficiently.ResultsThe thermotolerant strain GT48 was generated by adaptive laboratory evolution in batch and chemostat cultures under temperature increments until 48 °C. The strain GT48 was able to grow and ferment glucose to d-lactate at 47 °C. It was found that a pH of 6.3 conciliated with GT48 growth and cellulase activity of a commercial cocktail. Hence, this pH was used for the SSF of a diluted acid-pretreated corn stover (DAPCS) at a solid load of 15% (w/w), 15 FPU/g-DAPCS, and 47 °C. Under such conditions, the strain GT48 exhibited remarkable performance, producing d-lactate at a level of 1.41, 1.42, and 1.48-fold higher in titer, productivity, and yield, respectively, compared to parental strain at 45 °C.ConclusionsIn general, our results show for the first time that a thermal-adapted strain of E. coli is capable of being used in the simultaneous saccharification and fermentation process without pre-saccharification stage at high temperatures.

Effects of Climate Change on Temperature Sensitivity of Vegetation Growth in Huang-Huai-Hai Plain: Spatial–Temporal Dynamics and Ecological Adaptability

This paper explores the optimal temperature change in normalized difference vegetation index (NDVI) growth in the Huang-Huai-Hai Plain under the background of climate change, aiming to better cope with the impact of global warming on vegetation growth. The temporal and spatial variation characteristics of the NDVI and temperature factors were analyzed by using the NDVI, average temperature (Tavg), maximum temperature (Tmax) and minimum temperature (Tmin) datasets from 1982 to 2020. Through the Buishand U test and sliding slope detection, 1998 was determined to be a year of abrupt climate change. Furthermore, SHAP important feature analysis, a generalized additive model, correlation analysis, and other methods were used to identify the trend in the optimum temperature of vegetation growth before and after climate change. The results showed that (1) from 1982 to 2020, Tavg, Tmax, Tmin, and the NDVI in Huang-Huai-Hai Plain showed a significant upward trend. At the same time, the spatial distribution of these indicators shows the distribution characteristics of high in the south and low in the north. (2) The NDVI was positively correlated with Tavg, Tmax, and Tmin, and the correlation with Tmin was most significant. (3) The most suitable Tavg, Tmax, and Tmin intervals for vegetation growth were 20~30 °C, 25~35 °C, and 16~25 °C, respectively. (4) The optimum temperature range of vegetation growth was expanded after climate change, and the change rates of the Tavg and Tmax lower limits reached 24% and 25%, respectively, under the best condition of vegetation growth. (5) After abrupt climate change, the temperature suitable for vegetation growth increased significantly in the northern part of the plain but decreased slightly in the southern part.

Hidden pathogen risk in mature compost: Low optimal growth temperature confers pathogen survival and activity during manure composting

Livestock manure is a major reservoir for pathogens, posing significant environmental risks if used untreated. The efficacy of composting in fully inactivating pathogens remains controversial, particularly regarding the influence of their optimal growth temperature (OGT). This study investigated the composition and dynamic changes of pathogen communities and virulence factors (VFs) during the composting of chicken, bovine, ovine, and swine manure. We identified 134 pathogens across 16 composting piles, with ten pathogens exhibited increased abundance and transcriptional activity in curing phase. They included high-risk VFs-carrying pathogens, such as Mycolicibacterium thermoresistibile and Mycolicibacterium phlei, indicating the hidden pathogen risk in mature compost. Community-scale analyses revealed a linkage of these pathogens’ survival with their low OGT and an increased number of heat shock proteins (HSPs), enabling them to tolerate high temperatures and regrow. Integrating our data with prior composting studies, we found that the surviving pathogens express 42 VFs and their persistence in mature compost was a widespread issue, highlighting a greater risk of pathogen spread than previously thought. Finally, we compiled the 134 pathogens and 1009 VFs into a comprehensive Environmental Risk of Compost Pathogens (ERCP) catalog, providing a valuable resource for routine pathogen surveillance.

Winter torpor patterns of tricolored bats (Perimyotis subflavus) in the southeastern United States

Abstract The Tricolored Bat (Perimyotis subflavus) has suffered significant population declines in much of its geographic range due to white-nose syndrome (WNS). Our aim was to describe the torpor patterns of tricolored bats within the southeastern United States to further our understanding of their winter ecology and potential susceptibility to WNS in currently unimpacted areas based on data from bats in both a WNS-affected hibernaculum and an unaffected hibernaculum. We placed temperature-sensitive radio transmitters on tricolored bats in a site in northwestern South Carolina that was WNS-positive and another site in northwestern Florida that was WNS-negative, and determined torpid and arousal skin temperatures (TSK), torpor bout duration (TBD), and arousal duration (AD) during 3 winters. Mean hibernacula temperature (TH) and vapor pressure deficit (VPDH) in both hibernacula were within the range of optimal Pseudogymnoascus destructans (Pd) growth (TH = 12.7 to 13.6 °C, VPDH = 0.028 to 0.059 kPA). Mean torpid TSK was 15.7 ± 0.1 °C and mean TBD was 4.1 ± 0.2 days across sites. Sex was the best predictor of TBD with males having significantly longer TBD than females. Torpid TSK was positively related to TH and negatively related to VPDH. Because the TSK of a bat was similar to the optimal growth temperatures of Pd, our findings suggest that even though winters in the southeastern United States are more benign than in other parts of the Tricolored Bat range, the warmer temperatures in southern hibernacula may provide optimal conditions for the growth of Pd. Greater understanding of the physiological responses of tricolored bats in hibernacula across their range will provide important data on the potential for WNS morbidity and mortality in unaffected areas and allow for a better distribution of resources for prevention and treatment of WNS.

Biological characterization and in vitro fungicide screening of a new causal agent of walnut leaf spot in Guizhou Province, China.

Walnut (Juglans regia L.) is a widely grown nut plant worldwide, including in Guizhou Province, located in southwest China. The high quality and special taste make Guizhou walnuts, particularly those produced in Hezhang County, a "Chinese National Geographical Indication Product" that substantially contributes to the local economy and grower's income. In July 2022, a serious occurrence of leaf spot disease was observed in a walnut plantation area, Shuitang Town, Hezhang County, Guizhou Province, China (27°07'67″N, 104°64'61″E). The causal agent was identified as Didymella segeticola through morphological characterization and amplification and sequencing of the internal transcribed spacer (ITS) region, beta-tubulin (TUB) gene, and glyceraldehyde-3-phosphate dehydrogenase (G3PD) gene. Koch's postulates, including re-isolation and identification, were performed to confirm its pathogenicity on healthy leaves. To our knowledge, this is the first report of D. segeticola causing leaf spot on walnuts worldwide. Further, to determine its biological characteristics, which could be utilized for future disease management, the effects of temperature, light, and carbon and nitrogen resources on mycelial growth, conidia production, and conidia germination and the effects of humidity on conidia germination were studied. The optimum temperature for mycelial growth of representative strain D. segeticola C27 was 20°C. Increasing the light period significantly decreased conidia production and conidia germination. Maltose and beef extract were the best carbon and nitrogen sources, respectively, for the pathogen. Conidia germination was enhanced at 90% humidity. In vitro screening of effective fungicides was conducted. Among the 20 screened fungicides, difenoconazole showed the best inhibition rate, with an EC50 (concentration for 50% of the maximal effect) of 0.0007 μg/mL. Tetramycin also showed sufficient inhibitory effects against D. segeticola, with an EC50 value of 0.0009 μg/mL. Our study provides new insights into the causal agent of walnut leaf spot in Guizhou, China, as well as the first pathogen characteristics and promising candidate fungicides for its management.

Biological Characterization and Fungicide Sensitivity of Dactylobotrys graminicola Causing Oat Spikelet Rot in China

Oat (Avena sativa) is a significant cereal crop that is extensively cultivated in temperate regions and is suitable for growth at higher elevations. The damage degree and epidemic area of oat spikelet rot caused by Dactylobotrys graminicola are generally increasing and spreading. Mycelium growth rate method was used to identify biological characteristics and in vitro fungicide screenings of D. graminicola. The results show that sorbitol and casein tryptone were the best carbon and nitrogen source for the D. graminicola, respectively. The optimal temperature for mycelium growth and conidia production of the D. graminicola was 20 °C; meanwhile, an acidic environment was shown to be conducive to mycelia growth, and alkaline facilitated conidia production. Among the ten tested fungicides, 20% Pydiflumetofen showed the best inhibition rate, with an EC50 (concentration for 50% of maximal effect) value of 0.005 mg/L; 30% Difenoconazole Propiconazole and 35% Metalaxyl-M Fludioxonil also showed sufficient inhibitory effects against D. graminicola, with EC50 value of 0.05 mg/L and 0.04 mg/L. Furthermore, we used artificial inoculation to determine the effectiveness of fungicide control in field, Trifloxystrobin 10%-Tebuconazole 20% with more than 90% control effectiveness, followed by 20% Pydiflumetofen. The results of this study not only revealed the biological characteristics of D. graminicola, but also provided effective candidate fungicides for the prevention and control of oat spikelet rot disease.

Tuft Dynamics and the Reproductive Phenology of Zostera caespitosa on the Southern Coast of Korea

The aim of study is to determine which environmental factors could influence the biological traits of Z. caespitosa, a unique tuft-forming seagrass. This study examined the dynamics of tufts and the growth of Z. caespitosa, along with the environmental factors. The reproductive traits were also examined to estimate the potential importance of sexual reproduction in population persistence. The density of tufts remained constant, and no new tufts produced through seedling recruitment were observed throughout the sampling period. On the other hand, the tuft size and growth exhibited clear seasonal manners and strong correlations with the water temperature, indicating that water temperature regulates the tuft dynamics and growth. The optimal growth temperature for Z. caespitosa at the study site was approximately ~22.5 °C during early summer, with growth severely inhibited during periods of high-water temperatures. Z. caespitosa was characterized by a low flowering percentage and fewer inflorescences, resulting in extremely low potential seed production. Z. caespitosa maintained its populations through clonal tuft growth with low sexual reproduction and restricted growth at high water temperatures. Hence, this seagrass species may be vulnerable to disturbances, exhibiting low resilience and facing a high risk of becoming a threatened species in coastal waters.

Probiotic Potential of Bacillus Strains Isolated from Traditional Cassava Ferments (Manihot esculenta Crantz)

ABSTRACT: Probiotic potentials of Bacillus strains isolated from traditional cassava ferments, notably their growth at different pH, bile salts, temperatures, NaCl and antibiotics, their inhibition of pathogenic bacteria, non-production of hemolytic enzymes as well as the formation of biofilm were studied. These different probiotic parameters were determined according to the referenced methods. The results obtained showed that all Bacillus strains resisted acidic pH with the highest growths (7.29± 1.40) × 108 CFU/mL and (5.14±0.15) × 108 CFU /mL obtained with Bacillus toyonensis respectively at pH 2 for 24 hours and at pH 3 for 4 hours. All Bacillus strains grow well at 37°C and 44°C, despite their optimum growth temperature of 30°C. They also showed good growth at different bile salt concentrations and were multi-resistance to antibiotics Ciprofloxacin (100%), as was B. subtilis to Rifampicin (100%) but they were multi-sensitive (100%) to Amoxicillin, Imipenem, Gentamycin, Penicillin, Vancomycin, Chloramphenicol and Rifampicin except B. pumilus and B. methylotrophicus which were sensitive to Rifampicin (77%). Bacillus strains inhibited more than half of the pathogens (80.27% with S. aureus and 65.09% with E. coli). No strain showed hemolytic activity but rather a good capacity to form a biofilm (optical density ranging from 0.663 ± 00 to 3.15 ± 02 nm).

Genomic characterization of antibiotic-resistant Staphylococcus epidermidis with observed shifts in optimal temperature.

Antibiotic resistance genes (ARGs) in the environment pose significant public health concerns and are influenced by conditions like temperature changes. We previously observed that resistance evolution to gentamicin and colistin affects optimal growth temperatures in Staphylococcus epidermidis isolates. Despite significant phenotype observations, the genetic basis remains unclear. We aim to identify the genetic changes linked to antibiotic resistance evolution that alter optimal growth temperature. Using whole-genome sequencing, we sequenced the genomes of gentamicin-resistant (GEN-1, GEN-2) and colistin-resistant (COL-4, COL-6) S. epidermidis isolates. Variant analysis with the BV-BRC bioinformatics tool identified genes involved in antibiotic resistance and temperature response. We found 12 genetic variants, including two unique to GEN-2 and one in COL-4. One shared mutation was observed in GEN-1 and GEN-2, and another in COL-4 and COL-6. Five mutations were shared among all isolates related to mobile gene elements, including a transposase IS4 family, two putative transposases, and two transposase-like insertion elements. Our findings indicate that the same genes involved in gentamicin and colistin resistance, especially those related to mobile genetic elements, may also play a crucial role in temperature response.

RNA language models predict mutations that improve RNA function.

Structured RNA lies at the heart of many central biological processes, from gene expression to catalysis. While advances in deep learning enable the prediction of accurate protein structural models, RNA structure prediction is not possible at present due to a lack of abundant high-quality reference data 1 . Furthermore, available sequence data are generally not associated with organismal phenotypes that could inform RNA function 2-4 . We created GARNET (Gtdb Acquired RNa with Environmental Temperatures), a new database for RNA structural and functional analysis anchored to the Genome Taxonomy Database (GTDB) 5 . GARNET links RNA sequences derived from GTDB genomes to experimental and predicted optimal growth temperatures of GTDB reference organisms. This enables construction of deep and diverse RNA sequence alignments to be used for machine learning. Using GARNET, we define the minimal requirements for a sequence- and structure-aware RNA generative model. We also develop a GPT-like language model for RNA in which overlapping triplet tokenization provides optimal encoding. Leveraging hyperthermophilic RNAs in GARNET and these RNA generative models, we identified mutations in ribosomal RNA that confer increased thermostability to the Escherichia coli ribosome. The GTDB- derived data and deep learning models presented here provide a foundation for understanding the connections between RNA sequence, structure, and function.

Isolation and characterization of a multidrug-resistant Staphylococcus aureus infecting phage and its therapeutic use in mice.

In recent years, the emergence of multidrug-resistant bacteria has limited the selection of drugs for treating bacterial infections, reduced clinical efficacy, and increased treatment costs and mortality. It is urgent to find alternative antibiotics. In order to explore a new method for controlling methicillin-resistant Staphylococcus aureus (S. aureus), this study isolated and purified a multidrug-resistant S. aureus broad-spectrum phage JPL-50 from wastewater. JPL-50 belongs to the Siphoviridae family after morphological observation, biological characterization, and transmission electron microscopy (TEM) fragmentation spectrum analysis. It can cleave 84% of tested S. aureus (168/200), in which 100% of tested mastitis-associated strains (48/48) and 72.04% of MRSA strains (67/93) were lysed. In addition, it has an optimal growth temperature of about 30°C, a high activity within a wide pH range (pH 3-10), and an optimal multiplicity of infection of 0.01. The one-step growth curve shows a latent time of 20 min, an explosive time of 80 min. JPL-50 was 16 927bp in length and was encoded by double-stranded DNA, with no genes associated with bacterial resistance or virulence factors detected. In a therapeutic study, injection of the phage JPL-50 once and for 7 times in 7 days protected 40% and 60% of the mice from fatal S. aureus infection, respectively. More importantly, JPL-50-doxycycline combination could effectively inhibit host S. aureus in vitro and reduce the use of doxycycline within 8 h. In conclusion, the bacteriophage JPL-50 has a wide lysis spectrum, high lysis rate, high tolerance to extreme environments, and moderate in vivo activity, providing ideas for developing multidrug-resistant S. aureus infections.

Genomic and metabolomic analysis of Latilactobacillus sakei DCF0720 for black soybean yogurt fermentation

Lactic acid bacteria are commonly used in plant-based fermentation to reduce off-flavor and improve sensory characteristics. However, there have been few studies on Latilactobacillus sakei for plant-based yogurt fermentation and, particularly, its metabolic features at the genomic level remain unclear. This study aims to analyze the fermentation characteristics of the L. sakei DCF0720 strain and compare genetics and metabolic relations. For this, DCF0720 was used to ferment the black soybean milk and conduct the physicochemical analysis and sensory test. The genomic and metabolic analyses were performed by complete genome sequencing and 500 MHz 1H NMR, respectively. As a result, DCF0720 exhibited enhanced fermentation performance and sensory evaluations at 37 °C compared to 30 °C, which is generally recognized as the optimal growth temperature for most L. sakei strains. It also produced flavor enhancing volatile compounds such as acetoin and hydroxyacetone, possessing all three key genes for acetoin biosynthesis. DCF0720 lacks 2,3-butanediol dehydrogenase, which leads to the inhibition of acetoin production. DCF0720 possesses a complete pathway to utilize primary black soybean carbon sources such as sucrose, raffinose, and stachyose. DCF0720 also possesses genes for the GH28 family, including the key enzymes in the hydrolysis of pectin substances, which means eliminating the main soybean nonstarch polysaccharides. This study demonstrates that DCF0720 is a suitable starter for plant-based yogurt fermentation, providing a better understanding of fermentation conditions with genetic and metabolic features for black soybean yogurt. Various carbon source utilization abilities with depth metabolic pathway analysis provide that DCF0720 can be employed to develop enhanced starter cultures for black soybean yogurt and diverse plant-based yogurts.

Isolation, Characterization and Optimization of Indigenous Petrol Degrading Bacteria from Oil Contaminated Soil

Petroleum-derived products like petrol, containing complex hydrocarbons, have catastrophic environmental effects, posing a universal challenge. Bioremediation is known as eco-friendly and safe technique for removal of hydrocarbon pollutants. In this study, indigenous bacteria were isolated from oil contaminated soils and screened for their biodegradation potential. The bacterial enrichment and isolation were done using selective media Bushnell-Haas supplemented with petrol as a sole carbon source. Out of fifteen isolated strains best two isolates S4P2 and S14P1 were selected on basis of DCPIP screening method. These isolates were identified as Pseudomonas chengduensis & Pseudomonas donghuensis by 16S rRNA gene sequencing. The growth parameters were optimized by one factor at a time. The optimum growth temperature for P.chengduensis & P. donghuensis was found to be 37°C at pH 7 with a substrate concentration of 1%.

Genomic signatures of cold adaptation in the family Colwelliaceae.

Psychrophily is a phenotype describing microbial growth at low temperatures; elucidating the biomolecular and genomic adaptations necessary for survival in the cold is important for understanding life in extreme environments on Earth and in outer space. We used comparative genomics and temperature growth experiments of bacteria from the family Colwelliaceae to identify genomic factors correlated with optimal growth temperature (OGT). A phylogenomic analysis of 67 public and 39 newly sequenced strains revealed three main clades of Colwelliaceae. Temperature growth experiments revealed significant differences in mean OGT by clade, wherein strains of Colwelliaceae had similar growth rates at -1°C but varied in their ability to tolerate 17°C. Using amino acid compositional indices, a multiple linear regression model was constructed to predict the OGT of these organisms (RMSE 5.2°C). Investigation of Colwelliaceae functional genes revealed a putative cold-adaptive gene cassette that was present in psychrophilic strains but absent in a closely related strain with a significantly higher OGT. This study also presents genomic evidence suggesting that the clade of Colwelliaceae containing Colwellia hornerae should be investigated as a new genus. These contributions offer key insights into the psychrophily phenotype and its underlying genomic foundation in the family Colwelliaceae.