Culture Temperature Research Articles

The Effect of Growth Conditions on Mycelial Run of Oyster Mushrooms spp. (Pleurotus spp.): Implication for Agricultural Practices

Background: The Pleurotus genus is one of the most investigated white-rot fungus due to its excellent ligninolytic characteristics. It is a tasty mushroom that also has a number of biological impacts due to the presence of essential bioactive compounds. Many usual fermentation parameters affect lignocellulolytic enzymes in basidiomycete fungi, such as medium composition, carbon-to-nitrogen ratio, pH, temperature, air composition etc. The survival and multiplication of Pleurotus mushrooms is dependent on a number of factors, which may function independently or interactive effect on the growth of mushroom. Grasp the difficulty of treating Pleurotus species mushrooms necessitates a fundamental understanding of their physical, chemical and biological characteristics. Methods: In this study, the effects of culture media, temperature, carbon sources, nitrogen sources, grain sources and agricultural waste as lignocellulosic substrate on the mycelium growth of five species of Pleurotus species for spawn production were studied. Several trials were designed to evaluate factors affecting mycelium growth of five oyster mushroom species. The experiments were conducted during October to February in the year 2019 to 2021. The experiments were carried out in three replications per treatment. Result: The results of the experiment indicated that potato dextrose agar (PDA) and Malt extract agar (MEA) were the most suitable media for the mycelium growth of all oyster mushrooms. The optimal temperature for mycelium growth of all the oyster mushroom species was obtained at 25±2oC. Mycelium growth of all the studied oyster mushroom was improved by carbon sources such as dextrose and glucose. The nitrogen source such as ammonium chloride and ammonium sulfate also gave the greatest values in mycelium colony diameter of mushroom. Wheat was found to be favourable for mycelium growth of all the oyster mushroom species. In addition, paddy straw and sugarcane residue were selected as suitable lignocellulosic substrate sources for mycelium growth of all the studied oyster mushrooms.

Astragaloside IV improved antioxidative stress capacity and related gene expression of the Keap1-Nrf2 pathway in grass carp (Ctenopharyngodon idella) hepatocytes under heat stress.

This study aims to investigate the protective effects of astragaloside IV (AS-IV) on the hepatocytes of grass carp (Ctenopharyngodon idella) on heat stress. Cultured cells were treated with AS-IV (0, 50, 100 and 200 μg/ml) at 28°C for 24 h and then exposed to heat stress by increasing the culturing temperature (32 ± 0.5°C) for 6h. The increased temperatures significantly reduced cell viability and superoxide dismutase (SOD) activity, and increased malondialdehyde (MDA) levels in the 0μg/ml AS-IV treatment group at 32°C, but the grass carp hepatocytes treated with 100 and 200 μg/ml AS-IV had significantly increased cell viability and SOD activity and decreased MDA levels. The mRNA levels of keap1a, keap1b, nrf2, gsh-px, cat, cu-zn sod, mgst1 and il-6 were significantly lower in the 0μg/ml AS-IV treatment group at 32°C, while those of keap1a, nrf2, gsh-px, cat, cu-zn sod, gstp1, ho-1 and il-6 were significantly higher in cells treated with 100 or 200 μg/ml AS-IV. Our findings indicate that AS-IV could enhance the antioxidative stress capacity of grass carp hepatocytes under heat stress, and its mechanism may be associated with the activation of the Keap1-Nrf2 pathway. Thus, these results provide new insights into how to alleviate heat stress in grass carp.

A high-yielding strain of indole-3-acetic acid isolated from food waste compost: metabolic pathways, optimization of fermentation conditions, and application

ABSTRACT Food waste is a potential resource to prepare microbial fertilizer. However, functional microorganisms derived from the food waste compost (FWC) are relatively lacking. We have isolated, identified, characterized and optimized a high-yielding indole-3-acetic acid (IAA) strain from FWC and further evaluated its growth promoting effect on plants. A IAA high-yielding strain, Providencia sp.Y, with an initial IAA yield of 139.98 mg L−1, was obtained through high-throughput screening, and identified by 16S rRNA gene sequence. The novel strain Y may simultaneously involve the following three pathways from L-tryptophan to IAA, which were identified using liquid chromatography–tandem mass spectrometry: (1) L-tryptophan—indole-3-ethanol—indole-3-acetaldehyde—indole-3-acetic acid; (2) L-tryptophan—1-hydroxy-indole-3-ethanol—indole-3-acetic acid; (3) L-tryptophan—indole-3-acetamide—indole-3-acetic acid. The most suitable comprehensive conditions for IAA production, which were optimized by single factor experiment, were: culture time 12 h, inoculation amount 2% (v/v), NaCl concentration 4% (w/v), culture temperature 25℃, initial pH = 5, and L-tryptophan concentration 3.0 g L−1. The yield of IAA after optimization was increased by 590.48%, from 139.98 mg L−1 (before optimization) to 966.54 mg L−1. Diluted 200-fold microbial suspension could significantly improve the growth of pakchoi seedlings. The seedling plant height, root length, leaf width, leaf length, and fresh weight with microbial suspension increased by 17.39%, 107.35%, 77.98%, 37.75%, and 215.38%, respectively, compared with those without microbial suspension. The increase was greater than that of commercial bacterial agents. In conclusion, this isolated strain can be used as an economical microbial inoculant and provides a new germplasm resource for developing microbial fertilizers.

OLA-1, an Obg-like ATPase, integrates hunger with temperature information in sensory neurons in C. elegans.

Animals detect changes in both their environment and their internal state and modify their behavior accordingly. Yet, it remains largely to be clarified how information of environment and internal state is integrated and how such integrated information modifies behavior. Well-fed C. elegans migrates to past cultivation temperature on a thermal gradient, which is disrupted when animals are starved. We recently reported that the neuronal activities synchronize between a thermosensory neuron AFD and an interneuron AIY, which is directly downstream of AFD, in well-fed animals, while this synchrony is disrupted in starved animals. However, it remained to be determined whether the disruption of the synchrony is derived from modulation of the transmitter release from AFD or from the modification of reception or signal transduction in AIY. By performing forward genetics on a transition of thermotaxis behavior along starvation, we revealed that OLA-1, an Obg-like ATPase, functions in AFD to promote disruption of AFD-AIY synchrony and behavioral transition. Our results suggest that the information of hunger is delivered to the AFD thermosensory neuron and gates transmitter release from AFD to disrupt thermotaxis, thereby shedding light onto a mechanism for the integration of environmental and internal state to modulate behavior.

A Lysosome-Activated Tetrahedral Nanobox for Encapsulated siRNA Delivery.

Tetrahedral framework nucleic acids (tFNAs) have attracted extensive attention as drug nanocarriers because of their excellent cellular uptake. However, for oligonucleotide cargos, tFNA mainly acts as a static delivery platform generated via sticky-ended ligation. Here, inspired by the original stable space inside the tetrahedral scaffold, a dynamic lysosome-activated tFNA nanobox is fabricated for completely encapsulating a short interfering RNA (siRNA) of interest. The closed tetrahedral structure endows cargo siRNA with greater resistance against RNase and serum and enables solid integration with the vehicle during delivery. Moreover, the pH-responsive switch of nanobox allows the controlled release of siRNA upon entry into lysosomes at cell culture temperature. Based on protective loading and active unloading, an excellent silencing effect on the target tumor necrosis factor alpha (TNFα) gene is achieved in in vitro and in vivo experiments. Conclusively, the nanobox offers a dynamic pH-sensitive confinement delivery system for siRNA and can be an extendable strategy for other small RNA.

Statistical Optimization of Novel Medium to Maximize the Yield of Exopolysaccharide From Lacticaseibacillus rhamnosus ZFM216 and Its Immunomodulatory Activity.

The traditional media used for the fermentation of Lactobacilli always contain carbohydrate polymers, which interfere with the analysis of the exopolysaccharide (EPS) produced by the bacteria. In this investigation, a novel medium formulation that could avoid such interference was successfully developed. The beef extract, yeast extract, and peptone used in this formulation were subjected to the removal of polysaccharides before use. The factors affecting the EPS production were optimized by a single factor test, Plackett–Burman design, and Box–Behnken design. The optimum formula was ascertained as: 7.5 g L–1 yeast extract, 12.5 g L–1 beef extract, 10 g L–1 peptone, 21.23 g L–1 maltose, 5.51 g L–1 yeast nitrogen base, 2 g L–1 K2HPO4, 5 g L–1 anhydrous sodium acetate, 2 g L–1 ammonium citrate, 0.58 g L–1 MgSO4⋅7H2O, 0.25 g L–1 MnSO4⋅H2O, and 1 mL L–1 Tween 80. The initial pH of the medium was 6.5. The optimized conditions for fermentation of the strain to produce EPS were as follows: seed size 1%, culture temperature 37°C, and culture time 20 h. Optimum results showed that EPS yield was 496.64 ± 3.15 mg L–1, being 76.70% higher than that of unoptimized conditions (281.07 ± 5.90 mg L–1). The EPS was mainly comprised of glucose and guluronic acid, with a weight average molecular weight of 19.9 kDa; it was also characterized by Fourier transform infrared spectroscopy and UV analysis. EPS was found to significantly enhance the phagocytic capacity, promote the NO, TNF-α, IL-1β, and IL-6 secretion, and improve mRNA expression of cytokines in RAW 264.7 macrophages, indicating its considerable immunomodulatory activity. Western bolt and immunofluorescence results demonstrated that the EPS was able to increase p65 nuclear translocation in the macrophages, indicating that EPS enhanced immunity via the NF-κB signaling pathway. EPS investigated in this work has potential as an attractive functional food supplement candidate for the hypoimmunity population.

Pathogenic Enterobacteriaceae require multiple culture temperatures for detection in Cannabis sativa L.

Background: Cannabis safety testing requires adequate detection of a broad class of bacteria known as Enterobacteria, from the family of Enterobacteriaceae. These organisms are responsible for many food-borne illnesses including gastroenteritis, and are common targets in the food testing industry. While all these organisms contain 16S DNA, not all of them grow on commercial culture-based platforms at a single culture temperature. Methods: We assessed four Enterobacteria (Aeromonas hydrophila, Pantoea agglomerans, Yersinia enterocolitica, Rahnella aquatilis) that vary in their preferred culture temperature, human pathogenicity and prevalence in cannabis. We cultured them on two different plating media and compared these results to two different qPCR assays. Results: All four bacteria grew on one plating medium at 30°C. 75% of them failed to grow at 36°C. Using a different plating medium, 75% grew at 30°C and zero grew at 36°C. Two different commercialy available quantitative PCR assays detected 100% of the organisms. Conclusions: Several Enterobacteria are highly medium- and temperature-sensitive, and can easily evade culture-based detection. Some of these bacteria are known to infect cannabis and may pose a clinical risk to cannabis trimmers or consumers. Quantitative PCR detected all of these species. Quantitative PCR is often criticized for failing to discern live versus dead DNA, but the definition of “live” is dependent on the culture medium and temperature used.

Design and Modeling of a Microfluidic Coral Polyps Culture Chip with Concentration and Temperature Gradients.

Traditional methods of cultivating polyps are costly and time-consuming. Microfluidic chip technology makes it possible to study coral polyps at the single-cell level, but most chips can only be analyzed for a single environmental variable. In this work, we addressed these issues by designing a microfluidic coral polyp culture chip with a multi-physical field for multivariable analyses and verifying the feasibility of the chip through numerical simulation. This chip used multiple serpentine structures to generate the concentration gradient and used a circuit to form the Joule effect for the temperature gradient. It could generate different temperature gradients at different voltages for studying the growth of polyps in different solutes or at different temperatures. The simulation of flow field and temperature showed that the solute and heat could be transferred evenly and efficiently in the chambers, and that the temperature of the chamber remained unchanged after 24 h of continuous heating. The thermal expansion of the microfluidic chip was low at the optimal culture temperature of coral polyps, which proves the feasibility of the use of the multivariable microfluidic model for polyp culture and provides a theoretical basis for the actual chip processing.

Polyamines produced by an extreme thermophile are essential for cell growth at high temperature.

An extreme thermophile, Thermus thermophilus grows at an optimum temperature of around 70°C and produces 16 different polyamines including long-chain and branched-chain polyamines. We found that the composition of polyamines in the thermophile cells changes with culture temperature. Long-chain and branched-chain polyamines (unusual polyamines) were increased in the cells grown at high temperature such as 80°C, but they were minor components in the cells grown at relatively lower temperature such as 60°C. The effects of polyamines on cell growth were studied using T. thermophilus HB8 ΔspeA deficient in arginine decarboxylase. Cell growth of this mutant strain was significantly decreased at 70°C. This mutant strain cannot produce polyamines and grows poorly at 75°C. It was also determined whether polyamines are directly involved in protecting DNA from DNA double-strand breaks (DSBs) induced by heat. Polyamines protected DNA against double-strand breaks. Therefore, polyamines play essential roles in cell growth at extremely high temperature through maintaining a functional conformation of DNA against DSBs and depurination.

Expression of membrane beta-barrel protein in E. coli at low temperatures: Structure of Yersinia pseudotuberculosis OmpF porin inclusion bodies

The recombinant OmpF porin of Yersinia pseudotuberculosis as a model of transmembrane protein of the β-barrel structural family was used to study low growth temperature effect on the structure of the produced inclusion bodies (IBs). This porin showed a very low expression level in E. coli at a growth temperature below optimal 37 °C. The introduction of a N-terminal hexahistidine tag into the mature porin molecule significantly increased the biosynthesis of the protein at low cultivation temperatures. The recombinant His-tagged porin (rOmpF-His) was expressed in E. coli at 30 and 18 °C as inclusion bodies (IB-30 and IB-18). The properties and structural organization of IBs, as well as the structure of rOmpF-His solubilized from the IBs with urea and SDS, were studied using turbidimetry, electron microscopy, dynamic light scattering, optical spectroscopy, and amyloid-specific dyes. IB-18, in comparison with IB-30, has a higher solubility in denaturants, suggesting a difference between IBs in the conformation of the associated polypeptide chains. The spectroscopic analysis revealed that rOmpF-His IBs have a high content of secondary structure with a tertiary-structure elements, including a native-like conformation, the proportion of which in IB-18 is higher than in IB-30. Solubilization of the porin from IBs is accompanied by a modification of its secondary structure. The studied IBs also contain amyloid-like structures. The results obtained in this study expand our knowledge of the structural organization of IBs formed by proteins of different structural classes and also have a contribution into the new approaches development of producing functionally active recombinant membrane proteins.

Low specific growth rate and temperature in fed-batch cultures of a beta-propeller phytase producing Pichia pastoris strain under GAP promoter trigger increased KAR2 and PSA1-1 gene expression yielding enhanced extracellular productivity

Previously, we showed that the methylotrophic yeast Pichia pastoris (syn. Komagataella phaffii) could produce and secrete the beta-propeller phytase FTEII in an active form under the control of the AOX1 promoter and methanol as the inductor. In this work, we engineered P. pastoris strains to construct a constitutive P. pastoris expression system (GAP promoter) and extracellularly produce the phytase FTEII. We optimized the culture conditions to increase the extracellular volumetric phytase productivity (Qp) and evaluated the impact of the optimization process on the physiological response of the host. Moreover, we analyzed the expression levels of the FTEII gene and endogenous genes for P. pastoris cells in cultures with the lowest and highest Qp to understand which processes (from heterologous gene expression to protein secretion) might be responsible for the increase in Qp. The results indicate that a low specific growth rate and temperature in the fed-batch phase increases the Qp, which was correlated with an upregulation of the KAR2 and PSA1–1/MPG1 genes rather than increased heterologous gene transcription.

Scalable Process for High-Yield Production of PfCyRPA Using Insect Cells for Inclusion in a Malaria Virosome-Based Vaccine Candidate.

Plasmodium falciparum cysteine-rich protective antigen (PfCyRPA) has been identified as a promising blood-stage candidate antigen to include in a broadly cross-reactive malaria vaccine. In the last couple of decades, substantial effort has been committed to the development of scalable cost-effective, robust, and high-yield PfCyRPA production processes. Despite insect cells being a suitable expression system due to their track record for protein production (including vaccine antigens), these are yet to be explored to produce this antigen. In this study, different insect cell lines, culture conditions (baculovirus infection strategy, supplementation schemes, culture temperature modulation), and purification strategies (affinity tags) were explored aiming to develop a scalable, high-yield, and high-quality PfCyRPA for inclusion in a virosome-based malaria vaccine candidate. Supplements with antioxidants improved PfCyRPA volumetric titers by 50% when added at the time of infection. In addition, from three different affinity tags (6x-His, 4x-His, and C-tag) evaluated, the 4x-His affinity tag was the one leading to the highest PfCyRPA purification recovery yields (61%) and production yield (26 mg/L vs. 21 mg/L and 13 mg/L for 6x-His and C-tag, respectively). Noteworthy, PfCyRPA expressed using High Five cells did not show differences in protein quality or stability when compared to its human HEK293 cell counterpart. When formulated in a lipid-based virosome nanoparticle, immunized rabbits developed functional anti-PfCyRPA antibodies that impeded the multiplication of P. falciparum in vitro. This work demonstrates the potential of using IC-BEVS as a qualified platform to produce functional recombinant PfCyRPA protein with the added benefit of being a non-human expression system with short bioprocessing times and high expression levels.

Reusing water in a biofloc culture system favors the productive performance of the Nile tilapia (Oreochromis niloticus) without affecting the health status

Freshwater scarcity is a global problem and tends to be more severe. Five treatments reusing different percentages of water from a commercial BFT tilapia farm were evaluated: R0 (0%), R25 (25%), R50 (50%), R75 (75%) and R100 (100%). The water variables, fish and biofloc proximate compositions, as well as productive fish response and blood parameters, were determined. During the cultivation period, dissolved oxygen, temperature, and pH were similar between treatments, while alkalinity, total suspended solids, chlorophyll a, total ammonia nitrogen, and nitrite, showed significant differences (P < 0.05). The best productive response was obtained in the treatments with the highest water reuse (P < 0.05). The protein content in biofloc (24.92–26.30%) and tilapia (63.21–63.80%) was similar between treatments. No physiological implications by reusing water were detected; hematocrit ranged from 24.67 to 28.67%, erythrocytes 2.01–2.31 × 106 cell/mm3, plasmatic glucose 73.45–79.93 mg/dL, and plasmatic proteins 3.20–3.58 g/dL. The results suggest that it is possible to reuse biofloc water, positively affecting water quality and productive response, and causing no adverse effect on the fish's health.

Adverse Effects of High Temperature On Mammary Alveolar Development In Vitro.

In the mammary glands during pregnancy, the alveolar buds are first branched from the mammary ducts after which they form the alveolar luminal structure for milk production postparturition. Body temperature could increase for several reasons, such as infectious disease and heat stress. We have previously reported that high temperature adversely effects on the lactation capacity of mouse mammary epithelial cells (MECs). However, it remains unclear how high temperature influences mammary morophogenesis during pregnancy. In this study, we investigated the effects of high temperature on this mammary alveolar development process using two types of culture models including embedded organoids of MECs in Matrigel; these models reproduced mammary alveolar bud induction and alveolar luminal formation. Results showed that a culture temperature of 41°C repressed alveolar bud induction and inhibited alveolar luminal formation. In addition, the treatment at 41°C decreased the number of proliferating mammary epithelial cells but did not affect cell migration. Levels of phosphorylated Akt, -ERK1/2, -HSP90, and -HSP27 were increased in organoids cultured at 41°C. The specific inhibitors of HSP90 and HSP27 exacerbated the disruption of organoids at 41°C but not at 37°C. Furthermore, the organoids precultured at 37 and 41°C in the alveolar luminal formation model showed differences in the expression levels of caseins and tight junction proteins, which express in MECs in lactating mammary glands, after induction of MEC differentiation by prolactin and dexamethasone treatment in vitro. These results suggest that elevated temperature directly hinders mammary alveolar development; however, heat shock proteins may mitigate the adverse effects of high temperatures.

Process optimization of vanillin production by conversion of ferulic acid by Bacillus megaterium.

Vanillin is an important flavoring and aromatic ingredient found mainly in the pods of the tropical plant vanilla and is widely used in the food industry. Attempts have been made to produce vanillin from ferulic acid esters in agricultural residues of wheat bran. The results showed that a strain with high tolerance to the substrate ferulic acid was isolated and screened from soil and identified as belonging to the genus Bacillus (Bacillus megaterium). The concentration of vanillin produced by this strain was 0.048 g L-1 , and the molar conversion of vanillin was 12.25%. The production of vanillin was optimized by orthogonal experiments. Beef pastes 6.0g L-1 , soybean meal 5.0g L-1 , magnesium sulfate heptahydrate 1.0g L-1 , iron(II) sulfate heptahydrate 1.0g L-1 , calcium chloride 1.0g L-1 , dipotassium hydrogen phosphate trihydrate 1.0g L-1 ; fermentation culture conditions were pH7.0, inoculum level 5%, loading volume 20%, ferulic acid 1.0g L-1 , fermentation culture temperature 35 °C. The concentration of vanillin obtained was 0.218 g L-1 . Finally, transcriptomic analysis of the strain samples before and after the optimization of the fermentation conditions was carried out to study the effect of the optimization of the fermentation conditions on the concentration of vanillin produced by the strain. This study provides a theoretical basis for further improving the yield of vanillin and gradually realizing efficient industrial production. © 2022 Society of Chemical Industry.

Investigation of the Relation between Temperature and M13 Phage Production via ATP Expenditure

M13 bacteriophage is a promising biomolecule capable of various bionano and material science applications. The biomaterial can self-assemble into matrices to fabricate bioscaffolds using high phage concentration and high phage purity. Previous studies aimed to acquire these conditions in large-scale phage production and have identified the optimal culture temperature range at 28–31 °C. However, explanations as to why this temperature range was optimal for phage production is absent from the work. Therefore, in this study, we identified the relation between culture temperature and M13 phage production using ATP expenditure calculations to comprehend the high yield phage production at the optimal temperature range. We extended a coarse-grained model for the evaluation of phage protein and ribosomal protein synthesis with the premise that phage proteins (a ribosomal protein) are translated by bacterial ribosomes in E. coli through expenditure of ATP energy. By comparing the ATP energy for ribosomal protein synthesis estimated using the coarse-grained model and the experimentally calculated ATP expenditure for phage production, we interpreted the high phage yield at the optimal temperature range and recognized ATP analysis as a reasonable method that can be used to evaluate other parameters for phage production optimization.

Some like it hot, some like it cold; proteome comparison of Leptospira borgpetersenii serovar Hardjo strains propagated at different temperatures

Leptospirosis is a global zoonotic disease affecting humans and livestock species. Bacterin vaccines lack cross protection between serogroups, and include multiple serovars propagated at 29 °C. Recent work demonstrated substantial variation in the transcriptome of identical species and serovars of Leptospira. Here, substantial differences in protein abundance profiles were identified in Leptospira borgpetersenii serovar Hardjo; strain HB203, which was isolated in the 1980s, compared to newer strains TC129 and TC273 isolated in 2016, and whether they were propagated at the routine temperature of 29 °C, compared to 37 °C which more closely emulates host infection. While 388 and 385 significantly differentially expressed (DE) proteins (FDR of 0.01) were identified in HB203 versus TC129, and HB203 versus TC273 when propagated at 29 °C respectively, only 66 and 4 DE proteins were identified in HB203 versus TC129, and HB203 versus TC273 when propagated at 37 °C respectively. Within each strain comparing temperatures, HB203 had 524 significantly DE proteins, TC129 had 347 DE proteins, and TC273 had 569 DE proteins. Data are available via ProteomeXchange with identifier PXD032831. Results highlight significant differential protein expression among identical serovars of L. borgpetersenii suggesting that bacterin vaccine design can benefit from consideration of strains employed and effects of temperature on growth. SignificanceLeptospirosis is a zoonotic disease caused by spirochete bacteria of the genus Leptospira. While leptospirosis affects over one million people per year, symptoms range vastly in severity from completely asymptomatic, to flu-like, to multi-organ failure and death in severe cases. Incidental hosts become infected after encountering pathogens directly from contact with another host, including domestic or wildlife animals, or indirectly from contaminated environments. Though animal vaccines exist, they lack cross protection across serogroups, and instead rely on inclusion of multiple carefully selected serovars from laboratory strains prepared at ~29 °C. Recent interest in gene expression at the Leptospira strain level, along with a newly achieved culture temperature of 37 °C (which more closely resembles host body temperature), led us to investigate the proteomic profiles of an older, established challenge strain HB203 in comparison to TC129 and TC273, two strains isolated in 2016 from abattoir cattle in the central United States. Herein, we identify substantial proteomic differences not only between strains of the same species and serovar, but notably between growth temperatures, collectively suggesting that bacterin vaccine composition may benefit from investigating strain selection and the temperature employed for growth of the bacteria used in bacterin preparation.

Expression of eg9 gene encoding endoglucanase GH8 derived from metagenomic DNA data of bacteria in humus around white rot fungi degrading woods, in Escherichia coli

Endoglucanase is an important enzyme participating in the hydrolysis of cellulose into oligosaccharides or glucoses can be used in a variety of industrial fields. A gene (code GL0183420 designated as eg9) of 1398 bp encoding for endoglucanase family GH8 was identified from metagenomic DNA data of bacteria in the humus surrounding wood hydrolyzed by white rot fungi. The 126 terminal nucleotides at 5' terminal of the gene encode for a signal peptide in gram-negative bacteria and the next 1269 nucleotides encode the endoglucanase GH8. In this study, the eg9 gene (lack of sequence encoding the signal peptid) coding for the mature endoglucanase was codon optimized for expression in E. coli, artificical synthesized, then inserted into pET22b(+) for gene expression in E. coli strains. Through a survey of 5 expressive strains, EG9 was overexpressed in Rosetta and C43 strains. However, at 30oC in LB medium, most of EG9 were expressed in the insoluble fraction, in which Rosetta was the best strain for synthesis of EG9. The enzyme EG9 can be overexpressed in Rosetta strain at a large range of OD600 from 0.2 to 1. After reducing the culture temperature to 25°C, 50% of EG9 was expressed in soluble fraction and exhibited good hydrolysis activity in CMC substrate on agar plate. The investigation of media showed that PE was the most suitable medium for the recombinant Rosetta strain grow and synthesize endoglucanase EG9. EG9 was well expressed at various IPTG concentrations from 0.05 to 0.9 mM. These results offer great potential for production of recombinant EG9 for enzyme properties research.

On anammox activity at low temperature: Effect of ladderane composition and process conditions

The application of partial nitritation-anammox (PN/A) under mainstream conditions can enable substantial cost savings at wastewater treatment plants (WWTPs), but how process conditions and cell physiology affect anammox performance at psychrophilic temperatures below 15 °C remains poorly understood. We tested 14 anammox communities, including 8 from globally-installed PN/A processes, for (i) specific activity at 10–30 °C, (ii) composition of membrane lipids, and (iii) microbial community structure. We observed that membrane composition and cultivation temperature were closely related to the activity of anammox biomasses. The size of ladderane lipids and the content of bacteriohopanoids were key physiological components related to anammox performance at low temperatures. We also indicate that the adaptation of mesophilic cultures to psychrophilic regime necessitates months, but in some cases can take up to 5 years. Interestingly, biomass enriched in the marine genus “Candidatus Scalindua” displayed outstanding potential for nitrogen removal from cold streams. Collectively, our comprehensive study provides essential knowledge of cold adaptation mechanism, will enable more accurate modelling and suggests highly promising target anammox genera for inoculation and set-up of anammox reactors, in particular for mainstream WWTPs.

Controlling and Monitoring of Temperature and Humidity of Oyster Mushrooms in Tropical Climates

Controlling the temperature and humidity of oyster mushroom cultivation is done manually by spraying air on the mushroom container so it takes a lot of time and effort. This is done to meet the requirements for growing oyster mushrooms which are strongly influenced by temperature and humidity conditions so that they can grow well. In this study, a device for controlling and monitoring the temperature and humidity of oyster mushroom cultivation was made automatically based on Arduino UNO. This tool can regulate and monitor the temperature and humidity in oyster mushroom cultivation automatically so that the temperature and humidity can be maintained without having to spend a lot of time and effort. The components used in building the automatic temperature and humidity controller for mushroom cultivation based on the Arduino UNO are the dht11 sensors, Arduino UNO, L298N driver, relay, and 16x2 I2C LCD. From the results of the tests that have been carried out, it can be concluded that the temperature and humidity control and monitoring device for automatic oyster mushroom cultivation based on Arduino UNO has been able to work well in regulating and monitoring temperature and humidity as expected.