Enrichment performance and salt tolerance of polyhydroxyalkanoates (PHAs) producing mixed cultures under different saline environments.

The key to the resource recycling of saline wastes in form of polyhydroxyalkanoates (PHA) is to enrich mixed cultures with salt tolerance and PHA synthesis ability. However, the comparison of saline sludge from different sources and the salt tolerance mechanisms of salt-tolerant PHA producers need to be clarified. In this study, three kinds of activated sludge from different salinity environments were selected as the inoculum to enrich salt-tolerant PHA producers under aerobic dynamic feeding (ADF) mode with butyric acid dominated mixed volatile fatty acid as the substrate. The maximum PHA content (PHAm) reached 0.62 ± 0.01, 0.62 ± 0.02, and 0.55 ± 0.03 g PHA/g VSS at salinity of 0.5%, 0.8%, and 1.8%, respectively. Microbial community analysis indicated that Thauera, Paracoccus, and Prosthecobacter were dominant salt-tolerant PHA producers at low salinity, Thauera, NS9_marine, and SM1A02 were dominant salt-tolerant PHA producers at high salinity. High salinity and ADF mode had synergistic effects on selection and enrichment of salt-tolerant PHA producers. Combined correlation network with redundancy analysis indicated that trehalose synthesis genes and betaine related genes had positive correlation with PHAm, while extracellular polymeric substances (EPS) content had negative correlation with PHAm. The compatible solutes accumulation and EPS secretion were the main salt tolerance mechanisms of the PHA producers. Therefore, adding compatible solutes is an effective strategy to improve PHA synthesis in saline environment.

Formulation of biogenic fluorescent pigmented PHB nanoparticles from Rhodanobacter sp. for drug delivery.

Biogenic nanoparticles (NPs) have emerged as promising therapeutic formulations in effective drug delivery. Despite of various positive attributes, these NPs are often conjugated with various cytotoxic organic fluorophores for bioimaging, thereby reducing its effectiveness as a potential carrier. Herein, we aim to formulate biogenic fluorescent pigmented polyhydroxybutyrate (PHB) NPs from Rhodanobacter sp. strain KT31 (OK001852) for drug delivery. The bacterial strain produced 0.5 g L-1 of polyhydroxyalkanoates (PHAs) from 2.04 g L-1 of dry cell weight (DCW) under optimised conditions via submerged fermentation. Further, structural, thermal, and morphological charactersiation of the extracted PHAs was conducted using advance analytical technologies. IR spectra at 1719.25 cm-1 confirmed presence of C = O functional group PHB. NMR and XRD analysis validated the chemical structure and crystallinity of PHB. TG-DTA revealed Tm (168 °C), Td (292 °C), and Xc (35%) of the PHB. FE-SEM imaging indicated rough surface of the PHB film and the biodegradability was confirmed from open windro composting. WST1 assay showed no significant cell death (> 50%) from 100 to 500 µg/mL, endorsing non-cytotoxic nature of PHB. PHB NPs were uniform, smooth and spherical with size distribution and mean zeta potential 44.73 nm and 0.5 mV. IR and XRD peaks obtained at 1721.75 cm-1 and 48.42 Å denoted C = O and crystalline nature of PHB. Cell proliferation rate of PHB NPs was quite significant at 50 µg/mL, establishing the non-cytotoxic nature of NPs. Further, in vitro efficacy of the PHB NPs needs to be evaluated prior to the biomedical applications.

Cloning, Overexpression and Application of Lipase from Thermotolerant Bacillus subtilis TTP-06 in the Degradation of Polyhydroxyalkanoate.

Polyhydroxyalkanoates (PHAs) constitute a principal group of bio-degradable polymers that are produced by certain microbes under limited supply of nutrients. PHA is a linear polyester that comprises of 3-hydroxy fatty acid monomers. Triacylglycerol acylhydrolases are known to catalyze the hydrolysis of ester linkages and in turn they are beneficial in the degradation of PHA. In present study, lipase-catalyzed degradation of PHA synthesized by Priestia megatarium POD1 was monitored. A gene from thermotolerant Bacillus subtilis TTP-06 that was capable of expressing lipase enzyme was amplified by PCR, cloned into a pTZ57R/T-vector, transferred to an expression vector pET-23a (+) and expressed in Escherichia coli BL21 (DE3) cells. The recombinant enzyme purified to 19.37-fold had a molecular weight of 30 kDa (SDS-PAGE analysis). Scanning Electron Microscopy (SEM) revealed changes in the surface morphology of native and treated PHA films. Further, changes in molecular vibrations were confirmed by Fourier Transform Infrared Spectroscopy. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-024-01329-z.

CRISPR/Cas9-targeted mutagenesis of TaDCL4, TaDCL5 and TaRDR6 induces male sterility in common wheat.

Phased, small interfering RNAs (phasiRNAs) are important for plant anther development, especially for male sterility. PhasiRNA biogenesis is dependent on genes like RNA polymerase 6 (RDR6), DICER-LIKE 4 (DCL4), or DCL5 to produce 21- or 24 nucleotide (nt) double-strand small RNAs. Here, we generated mutants of DCL4, DCL5 and RDR6 using CRISPR/Cas9 system and studied their effects on plant reproductive development and phasiRNA production in wheat. We found that RDR6 mutation caused sever consequence throughout plant development starting from seed germination and the dcl4 mutants grew weaker with thorough male sterility, while dcl5 plants developed normally but exhibited male sterility. Correspondingly, DCL4 and DCL5, respectively, specified 21- and 24-nt phasiRNA biogenesis, while RDR6 contributed to both. Also, the three key genes evolved differently in wheat, with TaDCL5-A/B becoming non-functioning and TaRDR6-A being lost after polyploidization. Furthermore, we found that PHAS genes (phasiRNA precursors) identified via phasiRNAs diverged rapidly among sub-genomes of polyploid wheat. Despite no similarity being found among phasiRNAs of grasses, their targets were enriched for similar biological functions. In light of the important roles of phasiRNA pathways in gametophyte development, genetic dissection of the function of key genes may help generate male sterile lines suitable for hybrid wheat breeding.

Reclamation of chromium-contaminated soil by native Cr(VI)-reducing and PHA-accumulating Bacillus aryabhattai CTSI-07.

Reclamation of chromium-contaminated soil by bacteria is a big confront concerning to soil health restoration, food safety, and environmental protection. Herein, the chromium-resistant Bacillus aryabhattai CTSI-07 (MG757377) showed resistance to 1000 and 300 ppm of Cr(VI) in nutrient rich Luria Bertani (LB) and nutrient-deficient sucrose low phosphate (SLP) medium, respectively. It reduced 96.7% of Cr(VI) from contaminated soil in the presence of 100 ppm of Mg within 96 h under optimized conditions. Furthermore, Cr(VI) reduction by the bacteria was validated by Fourier transform infrared spectroscopic (FTIR) and X-ray diffraction (XRD) analysis. Besides Cr(VI) reduction, the bacterial strain also showed plant growth promoting traits like N2 fixation and indole acetic acid (IAA) production. On the other hand, transmission electron microscopy (TEM) imaging confirmed polyhydroxyalkanoates' (PHAs) granule accumulation and 0.5 g/l of PHAs was extracted from bacterial cell using SLP medium. Infra-red (IR) spectra and proton nuclear magnetic resonance (1H NMR) chemical shift patterns established the PHAs as polyhydroxybutyrate (PHB). Melting (Tm) and thermal degradation (Td) temperature of the PHB were 169 °C and 275 °C, respectively, as evident from thermogravimetry differential thermal analysis (TG-DTA). Atomic force microscopic (AFM) imaging depicted that the PHB film surface was rough and regular. Furthermore, the multi-metal-resistant, plant growth-promoting, and PHB-producing bacteria could reduce 99.82% of Cr(VI) from contaminated soil within 120 days in pot culture. Thus, it can be used for long-term reclamation of chromium-contaminated soil to restore soil health, provide food safety, and environmental protection.

Reprocessing of side-streams towards obtaining valuable bacterial metabolites.

Every year, all over the world, the industry generates huge amounts of residues. Side-streams are most often used as feed, landfilled, incinerated, or discharged into sewage. These disposal methods are far from perfect. Taking into account the composition of the side-streams, it seems that they should be used as raw materials for further processing, in accordance with the zero-waste policy and sustainable development. The article describes the latest achievements in biotechnology in the context of bacterial reprocessing of residues with the simultaneous acquisition of their metabolites. The article focuses on four metabolites - bacterial cellulose, propionic acid, vitamin B12 and PHAs. Taking into account global trends (e.g. food, packaging, medicine), it seems that in the near future there will be a sharp increase in demand for this type of compounds. In order for their production to be profitable and commercialised, cheap methods of its obtaining must be developed. The article, in addition to obtaining these bacterial metabolites from side-streams, also discusses e.g. factors affecting their production, metabolic pathways and potential and current applications. The presented chapters provide a complete overview of the current knowledge on above metabolites, which can be helpful for the academic and scientific communities and the several industries. KEY POINTS: • The industry generates millions of tons of organic side-streams each year. • Generated residues burden the natural environment. • A good and cost-effective method of side-streams management seems to be biotechnology - reprocessing with the use of bacteria. • Biotechnological disposal of side-streams gives the opportunity to obtain valuable compounds in cheaper ways: BC, PA, vitmain B12, PHAs.

PHAs production by facultative anaerobic bacteria Bacillus cereus FM5 through submerged and solid-state fermentation under anoxic condition.

PHAs (polyhydroxyalkanoates) are the bio-polyester synthesized by different aerobic and anaerobic bacteria as energy storage granule. However, its synthesis by anaerobes or facultative anaerobes is an imperative part of their physiology via assimilating broad range of substrates than aerobes. Thus, three Gram positive facultative anaerobic PHAs producers viz., Enterococcus sp. FM3, Actinomyces sp. CM4 and Bacillus sp. FM5 were selected. Among them, Bacillus sp. FM5 showed higher cell biomass production in MSM (mineral salt medium) comprised of glucose & peptone as carbon & nitrogen source at pH 9, temperature 37 °C, inoculum 10% and incubation period 72 h. Under optimized condition, Bacillus sp. FM5 produced 0.89 and 1.5 g l-1 of PHAs through submerged and solid-state fermentation in anoxic condition. In-silico analysis confirmed the facultative anaerobic PHAs producing bacteria as Bacillus cereus FM5. IR spectra of PHAs illustrated a strong absorption peak at 1718.50 cm-1 representing carbonyl ester (C=O) functional group of PHB (polyhydroxybutyrate), belonging to the family PHAs. It is the first report demonstrating PHAs production by Bacillus cereus FM5 in anoxic condition through different bioprocess technology, which may pave the way in the arena of further biopolymer research.

Polyhydroxyalkanoates (PHAs) synthesis and degradation by microbes and applications towards a circular economy.

Overusing non-degradable plastics causes a series of environmental issues, inferring a switch to biodegradable plastics. Polyhydroxyalkanoates (PHAs) are promising biodegradable plastics that can be produced by many microbes using various substrates from waste feedstock. However, the cost of PHAs production is higher compared to fossil-based plastics, impeding further industrial production and applications. To provide a guideline for reducing costs, the potential cheap waste feedstock for PHAs production have been summarized in this work. Besides, to increase the competitiveness of PHAs in the mainstream plastics economy, the influencing parameters of PHAs production have been discussed. The PHAs degradation has been reviewed related to the type of bacteria, their metabolic pathways/enzymes, and environmental conditions. Finally, the applications of PHAs in different fields have been presented and discussed to induce comprehension on the practical potentials of PHAs.

Recovery of polyhydroxyalkanoates (PHAs) polymers from a mixed microbial culture through combined ultrasonic disruption and alkaline digestion.

PHAs are a form of cellular storage polymers with diverse structural and material properties, and their biodegradable and renewable nature makes them a potential green alternative to fossil fuel-based plastics. PHAs are obtained through extraction via various mechanical, physical and chemical processes after their intracellular synthesis. Most studies have until now focused on pure cultures, while information on mixed microbial cultures (MMC) remains limited. In this study, ultrasonic (US) disruption and alkaline digestion by NaOH were applied individually and in combination to obtain PHAs products from an acclimated MMC using phenol as the carbon source. Various parameters were tested, including ultrasonic sound energy density, NaOH concentration, treatment time and temperature, and biomass density. US alone caused limited cell lysis and resulted in high energy consumption and low efficiency. NaOH of 0.05-0.2 M was more efficient in cell disruption, but led to PHAs degradation under elevated temperature and prolonged treatment. Combining US and NaOH significantly improved the overall process efficiency, which could reduce energy consumption by 2/3rds with only minimal PHAs degradation. The most significant factor was identified to be NaOH dosage and treatment time, with US sound energy density playing a minor role. Under the semi-optimized condition (0.2 M NaOH, 1300 W L-1, 10 min), over 70% recovery and 80% purity were achieved from a 3 g L-1 MMC slurry of approximately 50% PHAs fraction. The material and thermal properties of the products were analyzed, and the polymers obtained from US + NaOH treatments showed comparable or higher molecular weight to previously reported results. The products also exhibited good thermal stability and rheological properties, compared to the commercial standard. In conclusion, the combined US and NaOH method has the potential in real application as an efficient process to obtain high quality PHAs from MMC, and cost-effectiveness can be further optimized.

Production of polyhydroxyalkanoate (PHA) copolymer from food waste using mixed culture for carboxylate production and Pseudomonas putida for PHA synthesis.

Production of polyhydroxyalkanoates (PHAs) with high concentration of carboxylate, that was accumulated from solid state fermentation (SSF) of food waste (FW), was tested using Pseudomonas putida strain KT2440. Mixed-culture SSF of FW supplied in a high concentration of carboxylate, which caused a high PHA production of 0.56 g PHA/g CDM under nutrients control. Interestingly, this high PHA fraction in CDM was almost constant at 0.55 g PHA/g CDM even under high nutrients concentration (25 mM NH4+), probably due to high reducing power maintained by high carboxylate concentration. PHA characterization indicated that the dominant PHA building block produced was 3-hydroxybutyrate, followed by 3-hydroxy-2-methylvalerate and 3-hydroxyhenxanoate. Carboxylate profiles before and after PHA production suggested that acetate, butyrate, and propionate were the main precursors to PHA via several metabolic pathways. Our result support that mixed culture SSF of FW for high concentration carboxylate and P. putida for PHA production enables sustainable production of PHA in cost-effective manners.

Identification and characterization of miRNAs and PHAS loci related to the early development of the embryo and endosperm in Fragaria × ananassa.

BACKGROUND: The strawberry fleshy fruit is actually enlarged receptacle tissue, and the successful development of the embryo and endosperm is essential for receptacle fruit set. MicroRNAs (miRNAs) and phased small interfering RNAs (phasiRNAs) play indispensable regulatory roles in plant growth and development. However, miRNAs and phasiRNAs participating in the regulation of strawberry embryo and endosperm development have yet to be explored. RESULTS: Here, we performed genome-wide identification of miRNA and phasiRNA-producing loci (PHAS) in strawberry seeds with a focus on those involved in the development of the early embryo and endosperm. We found that embryos and endosperm have different levels of small RNAs. After bioinformatics analysis, the results showed that a total of 404 miRNAs (352 known and 52 novel) and 156 PHAS genes (81 21-nt and 75 24-nt genes) could be found in strawberry seed-related tissues, of which four and nine conserved miRNA families displayed conserved expression in the endosperm and embryo, respectively. Based on refined putative annotation of PHAS loci, some auxin signal-related genes, such as CM3, TAR2, AFB2, ASA1, NAC and TAS3, were found, which demonstrates that IAA biosynthesis is important for endosperm and embryo development during early fruit growth. Additionally, some auxin signal-related conserved (miR390-TAS3) and novel (miR156-ASA1) trigger-PHAS pairs were identified. CONCLUSIONS: Taken together, these results expand our understanding of sRNAs in strawberry embryo and endosperm development and provide a genomic resource for early-stage fruit development.

Marine-Derived Actinomycetes: Biodegradation of Plastics and Formation of PHA Bioplastics-A Circular Bioeconomy Approach.

Plastics are present in the majority of daily-use products worldwide. Due to society's production and consumption patterns, plastics are accumulating in the environment, causing global pollution issues and intergenerational impacts. Our work aims to contribute to the development of solutions and sustainable methods to mitigate this pressing problem, focusing on the ability of marine-derived actinomycetes to accelerate plastics biodegradation and produce polyhydroxyalkanoates (PHAs), which are biodegradable bioplastics. The thin plastic films' biodegradation was monitored by weight loss, changes in the surface chemical structure (Infra-Red spectroscopy FTIR-ATR), and by mechanical properties (tensile strength tests). Thirty-six marine-derived actinomycete strains were screened for their plastic biodegradability potential. Among these, Streptomyces gougerotti, Micromonospora matsumotoense, and Nocardiopsis prasina revealed ability to degrade plastic films-low-density polyethylene (LDPE), polystyrene (PS) and polylactic acid (PLA) in varying conditions, namely upon the addition of yeast extract to the culture media and the use of UV pre-treated thin plastic films. Enhanced biodegradation by these bacteria was observed in both cases. S. gougerotti degraded 0.56% of LDPE films treated with UV radiation and 0.67% of PS films when inoculated with yeast extract. Additionally, N. prasina degraded 1.27% of PLA films when these were treated with UV radiation, and yeast extract was added to the culture medium. The main and most frequent differences observed in FTIR-ATR spectra during biodegradation occurred at 1740 cm-1, indicating the formation of carbonyl groups and an increase in the intensity of the bands, which indicates oxidation. Young Modulus decreased by 30% on average. In addition, S. gougerotti and M. matsumotoense, besides biodegrading conventional plastics (LDPE and PS), were also able to use these as a carbon source to produce degradable PHA bioplastics in a circular economy concept.

fIdentification of B. napus small RNAs responsive to infection by a necrotrophic pathogen.

BACKGROUND: Small RNAs are short non-coding RNAs that are key gene regulators controlling various biological processes in eukaryotes. Plants may regulate discrete sets of sRNAs in response to pathogen attack. Sclerotinia sclerotiorum is an economically important pathogen affecting hundreds of plant species, including the economically important oilseed B. napus. However, there are limited studies on how regulation of sRNAs occurs in the S. sclerotiorum and B. napus pathosystem. RESULTS: We identified different classes of sRNAs from B. napus using high throughput sequencing of replicated mock and infected samples at 24 h post-inoculation (HPI). Overall, 3999 sRNA loci were highly expressed, of which 730 were significantly upregulated during infection. These 730 up-regulated sRNAs targeted 64 genes, including disease resistance proteins and transcriptional regulators. A total of 73 conserved miRNA families were identified in our dataset. Degradome sequencing identified 2124 cleaved mRNA products from these miRNAs from combined mock and infected samples. Among these, 50 genes were specific to infection. Altogether, 20 conserved miRNAs were differentially expressed and 8 transcripts were cleaved by the differentially expressed miRNAs miR159, miR5139, and miR390, suggesting they may have a role in the S. sclerotiorum response. A miR1885-triggered disease resistance gene-derived secondary sRNA locus was also identified and verified with degradome sequencing. We also found further evidence for silencing of a plant immunity related ethylene response factor gene by a novel sRNA using 5'-RACE and RT-qPCR. CONCLUSIONS: The findings in this study expand the framework for understanding the molecular mechanisms of the S. sclerotiorum and B. napus pathosystem at the sRNA level.

Isolation and identification of low-density polyethylene degrading novel bacterial strains.

Plastics are usually made up of low-density polyethylene (LDPE) that serve as the environmental nuisance. The recalcitrant nature of plastics is a huge concern, whereas the increasing demand has made it difficult to handle the plastic waste that eventually leads to plastic pollution. In recent years, due to increasing demand and high pressure for its safe disposal, plastic biodegradation has gained a lot of attention. In the current study, four bacterial strains were isolated from the solid-waste dumpsites of Faisalabad, Pakistan, using enrichment culture technique. The isolated bacterial strains were capable of growing on media having polystyrene as the sole carbon source. Based on 16S rRNA gene sequencing and phylogenetic analysis of the isolated strains Serratia sp., Stenotrophomonas sp. and Pseudomonas sp. were identified as the potential strains for the biodegradation of LDPE. Serratia sp. resulted in 40% weight loss of the LDPE plastic pieces after 150 days of treatment. Stenotrophomonas sp. and Pseudomonas species resulted in 32 and 21% weight loss of the treated piece of plastics (LDPE), respectively. Polyethylene pieces were characterized by Fourier-transform infrared spectroscopy (FTIR) analysis before and after biodegradation. The FTIR spectra indicated that the isolated bacterial strains have a good potential to degrade LDPE. Future studies are required to investigate the bacterial genetic makeup, mechanisms of LDPE biodegradation and the factors that can enhance the biodegradable characteristics of these indigenously isolated bacterial strains.

A Review on the Utilization of Lignin as a Fermentation Substrate to Produce Lignin-Modifying Enzymes and Other Value-Added Products.

The lignocellulosic biomass is comprised of three major components: cellulose, hemicellulose, and lignin. Among these three, cellulose and hemicellulose were already used for the generation of simple sugars and subsequent value-added products. However, lignin is the least applied material in this regard because of its complex and highly variable nature. Regardless, lignin is the most abundant material, and it can be used to produce value-added products such as lignin-modifying enzymes (LMEs), polyhydroxyalkanoates (PHAs), microbial lipids, vanillin, muconic acid, and many others. This review explores the potential of lignin as the microbial substrate to produce such products. A special focus was given to the different types of lignin and how each one can be used in different microbial and biochemical pathways to produce intermediate products, which can then be used as the value-added products or base to make other products. This review paper will summarize the effectiveness of lignin as a microbial substrate to produce value-added products through microbial fermentations. First, basic structures of lignin along with its types and chemistry are discussed. The subsequent sections highlight LMEs and how such enzymes can enhance the value of lignin by microbial degradation. A major focus was also given to the value-added products that can be produced from lignin.

Recent advances in constructing artificial microbial consortia for the production of medium-chain-length polyhydroxyalkanoates.

Polyhydroxyalkanoates (PHAs) are a class of high-molecular-weight polyesters made from hydroxy fatty acid monomers. PHAs produced by microorganisms have diverse structures, variable physical properties, and good biodegradability. They exhibit similar physical properties to petroleum-based plastics but are much more environmentally friendly. Medium-chain-length polyhydroxyalkanoates (mcl-PHAs), in particular, have attracted much interest because of their low crystallinity, low glass transition temperature, low tensile strength, high elongation at break, and customizable structure. Nevertheless, high production costs have hindered their practical application. The use of genetically modified organisms can reduce production costs by expanding the scope of substrate utilization, improving the conversion efficiency of substrate to product, and increasing the yield of mcl-PHAs. The yield of mcl-PHAs produced by a pure culture of an engineered microorganism was not high enough because of the limitations of the metabolic capacity of a single microorganism. The construction of artificial microbial consortia and the optimization of microbial co-cultivation have been studied. This type of approach avoids the addition of precursor substances and helps synthesize mcl-PHAs more efficiently. In this paper, we reviewed the design and construction principles and optimized control strategies for artificial microbial consortia that produce mcl-PHAs. We described the metabolic advantages of co-cultivating artificial microbial consortia using low-value substrates and discussed future perspectives on the production of mcl-PHAs using artificial microbial consortia.

Mitosis-related phosphorylation of the eukaryotic translation suppressor 4E-BP1 and its interaction with eukaryotic translation initiation factor 4E (eIF4E).

Eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1) inhibits cap-dependent translation in eukaryotes by competing with eIF4G for an interaction with eIF4E. Phosphorylation at Ser-83 of 4E-BP1 occurs during mitosis through the activity of cyclin-dependent kinase 1 (CDK1)/cyclin B rather than through canonical mTOR kinase activity. Here, we investigated the interaction of eIF4E with 4E-BP1 or eIF4G during interphase and mitosis. We observed that 4E-BP1 and eIF4G bind eIF4E at similar levels during interphase and mitosis. The most highly phosphorylated mitotic 4E-BP1 isoform (δ) did not interact with eIF4E, whereas a distinct 4E-BP1 phospho-isoform, EB-γ, phosphorylated at Thr-70, Ser-83, and Ser-101, bound to eIF4E during mitosis. Two-dimensional gel electrophoretic analysis corroborated the identity of the phosphorylation marks on the eIF4E-bound 4E-BP1 isoforms and uncovered a population of phosphorylated 4E-BP1 molecules lacking Thr-37/Thr-46-priming phosphorylation. Moreover, proximity ligation assays for phospho-4E-BP1 and eIF4E revealed different in situ interactions during interphase and mitosis. The eIF4E:eIF4G interaction was not inhibited but rather increased in mitotic cells, consistent with active translation initiation during mitosis. Phosphodefective substitution of 4E-BP1 at Ser-83 did not change global translation or individual mRNA translation profiles as measured by single-cell nascent protein synthesis and eIF4G RNA immunoprecipitation sequencing. Mitotic 5'-terminal oligopyrimidine RNA translation was active and, unlike interphase translation, resistant to mTOR inhibition. Our findings reveal the phosphorylation profiles of 4E-BP1 isoforms and their interactions with eIF4E throughout the cell cycle and indicate that 4E-BP1 does not specifically inhibit translation initiation during mitosis.

Evolution of PHAS loci in the young spike of Allohexaploid wheat.

BACKGROUND: PhasiRNAs (phased secondary siRNAs) play important regulatory roles in the development processes and biotic or abiotic stresses in plants. Some of phasiRNAs involve in the reproductive development in grasses, which include two categories, 21-nt (nucleotide) and 24-nt phasiRNAs. They are triggered by miR2118 and miR2275 respectively, in premeiotic and meiotic anthers of rice, maize and other grass species. Wheat (Triticum aestivum) with three closely related subgenomes (subA, subB and subD), is a model of allopolyploid in plants. Knowledge about the role of phasiRNAs in the inflorescence development of wheat is absent until now, and the evolution of PHAS loci in polyploid plants is also unavailable. RESULTS: Using 261 small RNA expression datasets from various tissues, a batch of PHAS (phasiRNA precursors) loci were identified in the young spike of wheat, most of which were regulated by miR2118 and miR2275 in their target site regions. Dissection of PHAS and their trigger miRNAs among the diploid (AA and DD), tetraploid (AABB) and hexaploid (AABBDD) genomes of Triticum indicated that distribution of PHAS loci were dominant randomly in local chromosomes, while miR2118 was dominant only in the subB genome. The diversity of PHAS loci in the three subgenomes of wheat and their progenitor genomes (AA, DD and AABB) suggested that they originated or diverged at least before the occurrence of the tetraploid AABB genome. The positive correlation between the PHAS loci or the trigger miRNAs and the ploidy of genome indicated the expansion of genome was the major drive force for the increase of PHAS loci and their trigger miRNAs in Triticum. In addition, the expression profiles of the PHAS transcripts suggested they responded to abiotic stresses such as cold stress in wheat. CONCLUSIONS: Altogether, non-coding phasiRNAs are conserved transcriptional regulators that display quick plasticity in Triticum genome. They may be involved in reproductive development and abiotic stress in wheat. It could be referred to molecular research on male reproductive development in Triticum.

Regulation of filamentation by bacteria and its impact on the productivity of compounds in biotechnological processes.

The bacteria wall fulfills important physiological functions at the cell, depending on its composition and organization. Many researches focused their studies in understanding the change of its properties not only in strength and permeability, but also in morphological plasticity due to both chemical and physical stresses. In particular, filamentation morphology is a cryptic phenomenon, with involve for great variety of bacteria, which allow them to acquire adaptive benefits. This phenotypic alteration consists of an alteration or lack of cell septation during the cell growth, as consequence of DNA damage or development of stress, such as nutritional factors, antibiotic resistance, low temperature, non-availability of oxygen, high osmolarity, and antimicrobial agents. These cells result in modification of elongation 10-50 times, thickness, chemical composition, and extent of cross-linking of the cell wall polymers than normal-shaped cells. Moreover, the advancement in the morphology engineering permitted the manipulation of the genes encoding the proteins belonging to the plasma membrane or cytoplasm, to have the control over the bacterial shapes and of the its cytoplasmatic environment. In biotechnology application, the intracellular space is primary used for a greater accumulation of secondary products, such as polyhydroxyalkanoates (PHAs). This review provides an insight into environmental induction of filamentation morphology and its use in biotechnological process. KEY POINTS: • Environmental stresses inducing filamentation morphology • Morphology engineering in biotechnological processes • Increase of polyhydroxyalkanoates (PHAs) accumulation.

The Role of Dactylis Glomerata and Diesel Oil in the Formation of Microbiome and Soil Enzyme Activity.

The global demand for petroleum contributes to a significant increase in soil pollution with petroleum-based products that pose a severe risk not only to humans but also to plants and the soil microbiome. The increasing pollution of the natural environment urges the search for effective remediation methods. Considering the above, the objective of this study was to determine the usability of Dactylis glomerata for the degradation of hydrocarbons contained in diesel oil (DO), as well as the effects of both the plant tested and DO on the biochemical functionality and changes in the soil microbiome. The experiment was conducted in a greenhouse with non-polluted soil as well as soil polluted with DO and phytoremediated with Dactylis glomerata. Soil pollution with DO increased the numbers of microorganisms and soil enzymes and decreased the value of the ecophysiological diversity index of microorganisms. Besides, it contributed to changes in the bacterial structure at all taxonomic levels. DO was found to increase the abundance of Proteobacteria and to decrease that of Actinobacteria, Acidobacteria, Chloroflexi, Gemmatimonadetes and Firmicutes. In the non-polluted soil, the core microbiome was represented by Kaistobacter and Rhodoplanes, whereas in the DO-polluted soil, it was represented by Parvibaculum and Rhodococcus. In soil sown with Dactylis glomerata, gasoline fraction (C6-C12) degradation was higher by 17%; mineral oil (C12-C35), by 9%; benzene, by 31%; anthracene, by 12%; chrysene, by 38%; benzo(a)anthracene, by 19%; benzo(a)pyrene, by 17%; benzo(b)fluoranthene, by 15%; and benzo(k)fluoranthene, by 18% than in non-sowed soil. To conclude, Dactylis glomerata proved useful in degrading DO hydrocarbons and, therefore, may be recommended for the phytoremediation of soils polluted with petroleum-based products. It has been shown that the microbiological, biochemical and chemical tests are fast and sensitive in the diagnosis of soil contamination with petroleum products, and a combination of all these tests gives a reliable assessment of the state of soils.