Carbohydrate Utilization Research Articles

Characterization of the probiotic properties of Lacticaseibacillus rhamnosus LR6 isolated from the vaginas of healthy Korean women against vaginal pathogens

The human microbiome exhibits intricate populations across the body, with the vaginal tract serving as an ecosystem characterized by the prevalence of the genus Lactobacillus. Disruptions in the vaginal microbiota, which are frequently linked to variables such as sexual activity, hormonal fluctuations, and excessive use of antibiotics, can result in vaginal dysbiosis and the development of diseases such as bacterial vaginosis (BV) and candidiasis. Lactobacillus species, owing to their capacity to create an acidic environment through the production of lactic acid, have a key function within this complex microbial community: they inhibit the growth of harmful microorganisms. This study aimed to investigate the genomic characteristics of L. rhamnosus LR6, a newly discovered strain isolated from the vaginal microbiota of 20 healthy women to assess its potential as a vaginal probiotic. We performed a comparative investigation of the genetic traits of L. rhamnosus using 45 publicly available genomes from various sources. We evaluated the genetic characteristics related to carbohydrate utilization, adhesion to host cells, and the presence of bacteriocin clusters. A comprehensive study was conducted by integrating in silico evaluations with experimental techniques to authenticate the physiological characteristics of strain LR6. We further used a rat model to assess the impact of L. rhamnosus LR6 administration on the changes in the gastrointestinal tract and the vaginal microbiome. The assessments revealed a significantly high inhibitory activity against pathogens, enhanced adherence to host cells, and high lactic acid production. Rat experiments revealed changes in both the fecal and vaginal microbiota; in treated rats, Firmicutes increased in both; Lactobacillaceae increased in the fecal samples; and Enterobacteriaceae decreased but Enterococcaceae, Streptococcaceae, and Morganellaceae increased in the vaginal samples. The study results provide evidence of the genetic characteristics and probiotic properties of LR6, and suggest that oral administration of L. rhamnosus LR6 can alter both gut and vaginal microbiome. Collectively, these findings establish L. rhamnosus LR6 as a highly promising candidate for improving vaginal health.

The dual role of TonB genes in turnerbactin uptake and carbohydrate utilization in the shipworm symbiont Teredinibacter turnerae.

This study highlights diversity in iron acquisition and regulation in bacteria. The mechanisms of iron acquisition and its regulation in Teredinibacter turnerae, as well as its connection to cellulose utilization, a hallmark phenotype of T. turnerae, expand the paradigm of bacterial iron acquisition. Two of the four TonB genes identified in T. turnerae exhibit functional redundancy and play a crucial role in siderophore-mediated iron transport. Unlike typical TonB genes in bacteria, none of the TonB genes in T. turnerae are clearly iron regulated. This unusual regulation could be explained by another important finding in this study, namely, that the two TonB genes involved in iron transport are also essential for cellulose utilization as a carbon source, leading to the expression of TonB genes even under iron-rich conditions.

DHA promotes healthy adipose tissue remodeling and carbohydrate utilization in grass carp (Ctenopharyngodon idellus) and largemouth bass (Micropterus salmoides)

Due to the wide usage of high-carbohydrate diets in aquaculture, improving the ability of fish to utilize high-carbohydrate diets is one of the important issues in aquaculture. Adipose tissue is an essential organ for storing energy and plays a vital role in glucose homeostasis. In this study, RNA sequencing reveals that docosahexaenoic acid (DHA) promoted the expression of the glucose metabolism related-genes in grass carp adipocytes, raising the hypothesis that DHA may attenuate the adverse effect of high-carbohydrate diets on fish via promoting glucose metabolism in adipose tissue. To verify this hypothesis, a total of 180 juvenile grass carp (14.24 ± 0.43 g) and a total of 180 largemouth bass (40.03 ± 0.12 g) were randomly distributed into 18 tanks (200 L), respectively, and fed with high-carbohydrate diets containing DHA. The results showed that high-carbohydrate diets promoted glycolysis and inhibited lipolysis and fatty acid β-oxidation, leading to the excessive accumulation of abdominal fat and adipose tissue inflammation. After feeding high-carbohydrate diets supplementation with DHA, glucose transporter type 4 (GLUT4) mediated-glucose uptake was increased in adipose tissue, resulting in significantly decreased blood glucose in grass carp and largemouth bass (P < 0.05). And then, the glucose was converted to triglyceride through the glucose-6-phosphate dehydrogenase (G6PD) mediated-pentose phosphate pathway, de novo synthesis of fatty acids and triglyceride (TG) synthesis. Subsequently, the resulting TG was broken down through lipolysis and fatty acid β-oxidation. These reprogrammed metabolic processes inhibited the excessive accumulation of abdominal fat. In addition, DHA attenuated inflammation in adipose tissue, and further reduced the levels of inflammatory cytokines in serum (P < 0.05), indicating that DHA promotes healthy adipose tissue remodeling. Ultimately, these benefits improved the growth performance of grass carp and largemouth bass fed with high-carbohydrate diets. Taken together, our study indicates that adipose tissue is an important target for improving the negative effects of high-carbohydrate diets, and DHA could promote healthy adipose tissue remodeling and improve carbohydrate utilization in fish by reprogramming the glucose and lipid metabolism in adipose tissues.

Effects of mepiquat chloride and plant population density on leaf photosynthesis and carbohydrate metabolism in upland cotton

BackgroundMepiquat chloride (MC) application and plant population density (PPD) increasing are required for modern cotton production. However, their interactive effects on leaf physiology and carbohydrate metabolism remain obscure. This study aimed to examine whether and how MC and PPD affect the leaf morpho-physiological characteristics, and thus final cotton yield. PPD of three levels (D1: 2.25 plants·m−2, D2: 4.5 plants·m−2, and D3: 6.75 plants·m−2) and MC dosage of two levels (MC0: 0 g·ha−2, MC1: 82.5 g·ha−2) were combined to create six treatments. The dynamics of nonstructual carbohydrate concentration, carbon metabolism-related enzyme activity, and photosynthetic attributes in cotton leaves were examined during reproductive growth in 2019 and 2020.ResultsAmong six treatments, the high PPD of 6.75 plants·m−2 combined with MC application (MC1D3) exhibited the greatest seed cotton yield and biological yield. The sucrose, hexose, starch, and total nonstructural carbohydrate (TNC) concentrations peaked at the first flowering (FF) stage and then declined to a minimum at the first boll opening (FBO) stage. Compared with other treatments, MC1D3 improved starch and TNC concentration by 5.4% ~ 88.4%, 7.8% ~ 52.0% in 2019, and by 14.6% ~ 55.9%, 13.5% ~ 39.7% in 2020 at the FF stage, respectively. Additionally, MC1D3 produced higher transformation rates of starch and TNC from the FF to FBO stages, indicating greater carbon production and utilization efficiency. MC1D3 displayed the maximal specific leaf weight (SLW) at the FBO stage, and the highest chlorophyll a (Chl a), Chl b, and Chl a + b concentration at the mid-late growth phase in both years. The Rubisco activity with MC1D3 was 2.6% ~ 53.2% higher at the flowering and boll setting stages in both years, and 2.4% ~ 52.7% higher at the FBO stage in 2020 than those in other treatments. These results provided a explanation of higher leaf senescence-resistant ability in MC1D3.ConclusionIncreasing PPD coupled with MC application improves cotton yield by enhancing leaf carbohydrate production and utilization efficiency and delaying leaf senescence.

The Molecular Mechanisms of Fuel Utilization during Exercise.

Exercise is widely recognized for its positive impact on human health and well-being. The process of utilizing substrates in skeletal muscle during exercise is intricate and governed by complex mechanisms. Carbohydrates and lipids serve as the primary fuel sources for skeletal muscle during exercise. It is now understood that fuel selection during exercise is not solely determined by physical activity itself but is also influenced by the overall metabolic state of the body. The balance between lipid and carbohydrate utilization significantly affects exercise capacity, including endurance, fatigue, and overall performance. Therefore, comprehensively understanding the regulation of substrate utilization during exercise is of utmost importance. The aim of this review is to provide an extensive overview of the current knowledge regarding the pathways involved in the regulation of substrate utilization during exercise. By synthesizing existing research, we can gain a holistic perspective on the intricate relationship between exercise, metabolism, and fuel selection. This advanced understanding has the potential to drive advancements in the field of exercise science and contribute to the development of personalized exercise strategies for individuals looking to optimize their performance and overall health.

Early programming effects of a hyperglucidic diet on carbohydrate and lipid metabolism in gibel carp (Carassius gibelio)

Previous nutritional studies have shown that intermediate metabolism in early fish development is highly plastic, and thus we hypothesized that there may be an early programming effect of a hyperglucidic diet on carbohydrate utilization in gibel carp. To test our hypothesis, gibel carp CAS Ⅴ (mean body weight: 0.10 g) were fed a high-carbohydrate/low protein (HC/LP) or low carbohydrate/high protein (LC/HP) diet for three weeks, and then were fed with normal feed for 12 weeks and a hyperglucidic diet for one week. We found that early HC/LP stimulus inhibited growth performance but altered the expression of glucose metabolism genes. After long-term feeding on the normal diet, the effects of early HC/LP stimulus were eliminated; these involved plasma metabolites, hepatic cholesterol, glycogen and triglyceride content, and glucose and lipid metabolism. However, the early HC stimulus group showed a better ability to maintain plasma glucose hemostasis when again given the HC diet. The capacity of carbohydrate and lipid metabolism in juvenile gibel carp was improved in the early HC diet group, as indicated by upregulated expression of genes related to glycolysis, lipid transport (gk, akt, srebp1, acc, fas, hsl, and acly) and downregulated expression of genes involved in gluconeogenesis (fbpase). Moreover, the early HC diet significantly upregulated AKT protein expression levels. The DNA methylation levels of akt in the HC/LP group were significantly lower than those in the LC/HP group. Overall, the study suggests that early HC stimulus in juvenile gibel carp can result in better carbohydrate utilization through DNA methylation of critical elements in the insulin signaling pathway.

Utilization of diverse oligosaccharides for growth by Bifidobacterium and Lactobacillus species and their in vitro co-cultivation characteristics

Various approaches have been used to study the relationship between prebiotics and probiotics. The utilization of different carbohydrates by probiotics depends on the biochemical properties of the enzymes and substrates required by the microbial strain. However, few studies have systematically analyzed the ability of probiotics to utilize different prebiotics. Here, we investigated the effects of prebiotics from different manufacturers on the proliferation of 13 strains of the Lactobacillus group and the genus Bifidobacterium co-cultured in vitro. Inulin, fructose-oligosaccharide (FOS), and galactose-oligosaccharide (GOS) had broad growth-promoting effects. FOS significantly promoted the proliferation of B. longum. When strains from Lactobacillus group and Bifidobacterium were co-cultured, FOS caused each strain to proliferate cooperatively. GOS was effectively used by L. rhamnosus and L. reuteri for energy and growth promotion. L. casei and L. paracasei fully metabolized inulin; these strains performed better than other strains from Lactobacillus group and Bifidobacterium. Media containing a mixture of oligosaccharides had stronger effects on the growth of B. animalis subsp. lactis, L. acidophilus, and L. rhamnosus than media containing single oligosaccharides. Thus, different oligosaccharides had different effects on the growth of probiotics, providing a scientific basis for the use of synbiotics in health and related fields.

Physiological and antioxidant responses associated with Sub1 gene introgressed rice (Oryza sativa L.) lines under complete submergence.

Rice is the only crop which is well adapted to aquatic environment but, it is unable to survive if completely submerged for several weeks. Breeding rice varieties with submergence tolerance is one of the best approaches to alleviate the adverse effect of submergence which requires the introgression of Sub1 gene into elite rice varieties. Hence, the study was undertaken to introgress submergence tolerant gene into the rice variety Jaya through Marker-Assisted Backcross Breeding. Also the physiological and biochemical responses like survival percentage, underwater shoot elongation, total carbohydrate content and superoxide dismutase activity were also studied in Sub1 introgressed lines. We could develop twenty Sub1 introgressed lines with Sub1 region of 3.1-5.1mb and with 80.0- 95.3% recurrent parent genome recovery. Sub1 introgressed Jaya lines and the tolerant checks FR13A and Swarna Sub1 had lower shoot elongation under water, higher superoxide dismutase activity (about 5 times) upto 4h after de-submergence which resulted in higher survival percentage. The reduced shoot elongation of tolerant varieties reduced the utilization of stored carbohydrate. Through our research we introgressed Sub1 gene into rice variety Jaya through Marker-Assisted Backcross Breeding and could study the physiological responses under submergence by which we confirmed the presence of Sub1 gene in these lines. These lines could be field evaluated and could be released as a new variety thus helping the farmers of flood prone areas of Kerala.

Sexual competition and light regimes interactively affect dimorphism and competitiveness of opposite sexes in Populus yunnanensis

Light, as the most important energy and environmental signal, exerts crucial impacts on plant-plant interactions and the composition of plant communities. However, little attention has been paid to understanding how females and males respond to sexual competition under different light conditions. In this study, we investigated morphological and physiological parameters between two sexes of Populus yunnanensis under intra- and intersexual competition in two light regimes, i.e., full light and shading conditions (equal to 55% full light). Under full-light conditions, males grown under intersexual competition exhibited greater above-ground biomass accumulation, specific leaf area (SLA), root-to-shoot ratio (R/S), non-structural carbohydrate (NSC) utilization efficiency, and a higher ability to maintain the balance of nitrogen (N) and phosphorus (P) content compared to females. These eco-physiological responses confer males with a competitive advantage over females under sufficient light conditions. In contrast, there were no significant sex-specific differences in biomass accumulation and relative competitive intensity (RCI) values under shade treatment. Under shading, the opposite sexes of P. yunnanensis exhibited mutual suppression of each other to varying degrees, showing similar competitive potential. These results demonstrate that the performance of plants in terms of morphology and physiology is strongly affected by patterns of sexual competition and light regimes. The asymmetry in sexual competition might be a crucial factor influencing the biased sex ratio of P. yunnanensis in natural habitats.

The hierarchy of sugar catabolization in Lactococcus cremoris.

Bacteria adapt to nutrient availability by regulating the synthesis of enzymes. Transcriptome- and multi-sugar growth studies suggest that Lactococcus cremoris represses genes involved in the catabolization of lower growth rate-supporting (lower quality) sugars in a hierarchical order. Furthermore, L. cremoris appears to always express genes involved in the catabolization of higher growth rate-supporting sugars (higher quality) relative to the sugar it is growing on. Here, we unraveled the sugar catabolization hierarchy by determining the sugar catabolizing capacity and the proteome of cells exponentially growing on glucose (µmax = 0.72 h-1), lactose (µmax = 0.6 h-1), galactose (µmax = 0.44 h-1), or maltose (µmax = 0.43 h-1). We found that L. cremoris can grow on 14 of the 96 sugars in a Biolog plate, with µmax ranging from 0.32 to 0.72 h-1. Proteome and catabolization rate measurements show that L. cremoris consistently prepares for the catabolization of higher-quality sugars, except trehalose. While cells were not prepared for the catabolization of most lower-quality sugars, some proteins related to fructose and lactose consumption were always present. Moreover, reducing the growth rate of glucose through salt stress had only a minor influence on the sugars that L. cremoris could catabolize. These findings demonstrate that the catabolization hierarchy is not strictly linked to absolute growth rate or sugar quality. Cells instantly catabolizing a higher-quality sugar require enhanced expression of ribosomal and nucleotide metabolism functions for growth rate maximization, whereas transitioning to lower-quality sugars requires enhanced synthesis of proteins related to arginine catabolism and mixed acid fermentation, besides sugar-specific catabolic proteins.IMPORTANCEThe availability of nutrients to microorganisms varies considerably between different environments, and changes can occur rapidly. As a general rule, a fast growth rate-typically growth on glucose-is associated with the repression of other carbohydrate utilization genes, but it is not clear to what extent catabolite repression is exerted by other sugars. We investigated the hierarchy of sugar utilization after substrate transitions in Lactococcus cremoris. For this, we determined the proteome and carbohydrate utilization capacity after growth on different sugars. The results show that the preparedness of cells for the utilization of "slower" sugars is not strictly determined by the growth rate. The data point to individual proteins relevant for various sugar transitions and suggest that the evolutionary history of the organism might be responsible for deviations from a strictly growth rate-related sugar catabolization hierarchy.

Why Bufo gargarizans tadpoles grow bigger in Pb-contaminated environments? The gut microbiota matter

The impacts of lead/Pb2+ on ecosystems have received widespread attention. Growth suppression is a major toxic effect of Pb compounds on aquatic animals, however, some studies have also reported their growth-promoting effects. These complex outcomes may be explained by anions that accompany Pb2+ or by the multiple toxic mechanisms/pathways of Pb2+. To examine these hypotheses, we tested how Bufo gargarizans tadpoles responded to Pb(NO3)2 (100 and 200 μg/L Pb2+) using transcriptomics and microbiomics, with NaNO3 and blank groups as controls. Tadpoles exposed to Pb(NO3)2 showed delayed development while increased somatic growth in a dose-dependent manner, which can be attributed to the effects of NO3- and Pb2+, respectively. Tadpole transcriptomics revealed that exposure to NO3- downregulated the MAPK pathway at transcriptional level, explaining the development-suppressing effect of NO3-; while Pb2+ upregulated the transcription of detoxification pathways (e.g., xenobiotics metabolism by cytochrome P450 and glutathione metabolism), indicating cellular stress and thus contradicting the growth advantage of Pb2+-exposed tadpoles. Pb2+ exposure changed the tadpole gut microbiota drastically, characterized by increased polysaccharides and carbohydrate utilization while decreased fatty acid and amino acid consumption according to microbial functional analysis. Similar gut microbial variations were observed in field-collected tadpoles from different Pb2+ environments. This metabolic shift in gut microbiota likely improved the overall food utilization efficiency and increased the allocation of fatty acids and amino acids to the host, explaining the growth advantage of Pb2+-exposed tadpoles. In summary, our results suggest multiple toxic pathways of Pb2+, and the gut microbiota may affect the pollution outcomes on animals.

Multiple TonB homologs are important for carbohydrate utilization by Bacteroides thetaiotaomicron.

The human gut microbiota, including Bacteroides, is required for the degradation of otherwise undigestible polysaccharides. The gut microbiota uses polysaccharides as an energy source, and fermentation products such as short-chain fatty acids are beneficial to the human host. This use of polysaccharides is dependent on the proper pairing of a TonB protein with polysaccharide-specific TonB-dependent transporters; however, the formation of these protein complexes is poorly understood. In this study, we examine the role of 11 predicted TonB homologs in polysaccharide uptake. We show that two proteins, TonB4 and TonB6, may be functionally redundant. This may allow for the development of drugs targeting Bacteroides species containing only a TonB4 homolog with limited impact on species encoding the redundant TonB6.

Comparative metabolomics analysis reveals dynamic changes in carbohydrate profiles of corms during the "relay growth" of konjac (Amorphophallus muelleri).

The type and content of carbohydrates in konjac corms are an essential factors in determining the quality of konjac; however, the pattern of carbohydrate changes and the mechanism regulating the development of mother and daughter corms in the "relay growth" process of Amorphophallus muelleri remain unclear. This study aimed to investigate changes in corm carbohydrates during the growth cycle of A. muelleri and to compare the carbohydrate composition and the expression of related genes between mother and daughter corms. Integrated metabolome and RNA-seq analyses identified 37 differential metabolites as well as 8074 genes that were differentially expressed between mother and daughter corms, the majority of which were involved in starch and sucrose metabolism. More than 80% of the differential metabolites, including sucrose and starch, tended to accumulate in the mother corms; however, konjac glucomannan (KGM), as one of the most important carbohydrates and its major component of the corm, accumulated in higher amounts in the daughter corms. In addition, the expression of invertase and alpha-amylase that promote the breakdown of sucrose and starch was 351.78- and 15.63-fold higher, respectively, in the daughter corm, whereas that of the starch synthesis gene AkWAXY was only 0.096 times as high as in the mother corms. Furthermore, the level of cellulose synthase-like protein G, which promotes KGM synthesis, was 3.85 times higher in daughter corms compared to mother corms. Thus, we inferred that the daughter and mother corms had two distinct carbohydrate utilization strategies. This study provides insights into temporal changes in carbohydrates during the growth cycle of A. muelleri.

Salt tolerant fungal endophytes alleviate the growth and yield of saline-affected wheat genotype PBW-343

The purpose of this work was to assess how salt-tolerant wheat endophytic fungi promoted the growth of salt-sensitive wheat after inoculation. The endophytic fungal assemblages from salt-tolerant wheat genotypes (KRL-213, KRL-210 and KRL-19) and from salt-sensitive wheat genotype (PBW-343) were characterized, identified and determined for the current study. Of the fifty fungal isolates collected from both the salt-tolerant and the salt-sensitive wheat genotypes, 8 isolates recovered from salt-tolerant varieties were found to be resistant at high salt concentrations. These 8 isolates were characterized through several biochemical tests, such as plant growth promoting assay, extracellular enzymatic assay, carbohydrate utilization assay, antagonism versus plants pathogens and capacity to promote wheat seedlings (pot experiments). All tests revealed the positive results for 4 fungal strains (K13TR/150, K19TR/200, K-19TL/150 and K-19TL/200). These 4 fungi were identified as Aspergillus medius (K19TR/200), Cladosporium parahalotolerant (K13TR/150), Aspergillus versicolor (K19TL/150) and Aspergillus nishimurae (K19TL/200) through 18 S rDNA sequencing. Out of these, C. parahalotolerant and A. medius showed the synergistic effect with each other, so these 2 isolates were used in further experiments. These 2 isolates were involved in increasing the root-shoot length, proline and MDA contents. SEM and fluorescence microscopy were used to detect endophytic fungal colonization in the root of seedlings. C. parahalotolerant and A. medius heavily colonized the roots and it was noticed on the 21st day of the growth phase. These findings imply that fungal isolates have the potential to confer stress tolerance to their respective hosts and may enhance the agricultural production in the future, especially considering the changes in climate.

Genomic and metabolic insights into the first host-associated isolate of Psychrilyobacter.

Although gut bacteria are vital to their hosts, few studies have focused on marine animals. Psychrilyobacter is frequently related to various marine animals, but its interaction with host remains unknown due to the lack of host-associated isolate or genomic information. Here, we combined cultivation-independent and cultivation-dependent methods to uncover the potential roles of Psychrilyobacter in the host abalone. The high-throughput sequencing and literature compiling results indicated that Psychrilyobacter is widely distributed in marine and terrestrial ecosystems with both host-associated and free-living lifestyles, but with a strong niche preference in the guts of marine invertebrates, especially abalone. By in vitro enrichment that mimicked the gut inner environment, the first host-related pure culture of Psychrilyobacter was isolated from the abalone intestine. Phylogenetic, physiological, and biochemical characterizations suggested that it represents a novel species named Psychrilyobacter haliotis B1. Carbohydrate utilization experiments and genomic evidence indicated that B1 can utilize diverse host-food-related monosaccharides and disaccharides but not polysaccharides, implying its potential role in the downstream fermentation instead of the upstream food degradation in the gut. Particularly, this strain showed potential to colonize the gut and benefit the host via different strategies, such as the short-chain fatty acids generation by fermenting peptides and/or amino acids, and the putative production of diverse vitamins and antibiotics to support the host growth and antipathogenicity. To our knowledge, strain B1 represents the first host-related pure culture of Psychrilyobacter; genomic and metabolic evidence showed some beneficial characteristics of the dominant gut anaerobe to the host. IMPORTANCE Psychrilyobacter is a globally distributed bacterial genus and with an inhabiting preference for guts of marine invertebrates. Due to the difficulty of cultivation and the limited genomic information, its role in host remains largely unknown. We isolated the first host-associated Psychrilyobacter species from abalone gut and uncovered its functional potential to the host through different mechanisms. Our findings provide some insights into the understanding of host-microbe interactions on a core taxon with the marine invertebrates, and the isolate may have an application potential in the protection of marine animals.

A strategic roadmap for carbohydrate utilization in crustaceans feed

AbstractCarbohydrates serve as essential macronutrients in aquaculture feeds, providing cost‐efficiency and numerous advantages, including energy supply, pellet stability, reduced ammonia excretion, and support for exoskeleton synthesis in crustaceans. Despite their significance, research on carbohydrate nutrition in crustaceans has been relatively limited compared to finfish. This comprehensive review addresses this knowledge gap by presenting contemporary insights into carbohydrate utilization in commercially important crustacean species, encompassing shrimps, prawns, crabs, lobsters, and crayfishes. The review underscores the pivotal role of carbohydrates, identifies limiting factors, and outlines strategies for enhancing efficiency. Wheat and sorghum/milo emerge as particularly promising carbohydrate sources. Nevertheless, determining species‐specific carbohydrate inclusion levels remains essential for further investigation. This review also emphasizes species‐specific distinctions in carbohydrate utilization during starvation, influenced by factors such as age, moulting stage, and digestive capacity. Challenging the misconception that carbohydrates are superfluous for crustaceans is imperative. Additional research to advance comprehension of their utilization mechanisms is vital. Enhanced knowledge of carbohydrate utilization can pave the way for economically sustainable and environmentally friendly feeds in crustacean aquaculture. Furthermore, exploring exogenous enzyme potential, optimizing pre‐treatment methodologies, and harnessing probiotics can further augment carbohydrate utilization. These advancements hold promise for bolstering the growth and sustainability of the crustacean industry, meeting the surging demand for seafood production while minimizing environmental impact.

Comparative genomics of Lactobacillus johnsonii reveals extensive intraspecific genetic variation

Lactobacillus johnsonii, as a microorganism widely presenting in the intestinal tract of mammals, dairy products, and poultry, possesses various probiotic characteristics. Currently, many research focused on the probiotic functions and industrial applications of L. johnsonii. In this study, 98 strains of L. johnsonii were subjected to comparative genomic analyses to explore its genetic diversity. The results indicated that based on ANI values, d-DDH values, phylogenetic analysis, and whole-genome comparison, the 98 strains of L. johnsonii were classified into two phylogenetic clusters. The carbohydrate utilization genes, bacteriocin operon, extracellular polysaccharide gene cluster, and bile salt hydrolase encoding genes in L. johnsonii shared common features and exhibited systematic differences based on phylogenetic clustering. The main reason for the high intra-species gene diversity of L. johnsonii might be differences in phages and other mobile genetic elements. This study provides new insights into the genomic features and functional genes of L. johnsonii.

GR-KLF15 pathway controls hepatic lipogenesis during fasting.

During periods of fasting, the body undergoes a metabolic shift from carbohydrate utilization to the use of fats and ketones as an energy source, as well as the inhibition of de novo lipogenesis and the initiation of gluconeogenesis in the liver. The transcription factor sterol regulatory element-binding protein-1 (SREBP-1), which plays a critical role in the regulation of lipogenesis, is suppressed during fasting, resulting in the suppression of hepatic lipogenesis. We previously demonstrated that the interaction of fasting-induced Kruppel-like factor 15 (KLF15) with liver X receptor serves as the essential mechanism for the nutritional regulation of SREBP-1 expression. However, the underlying mechanisms of KLF15 induction during fasting remain unclear. In this study, we show that the glucocorticoid receptor (GR) regulates the hepatic expression of KLF15 and, subsequently, lipogenesis through the KLF15-SREBP-1 pathway during fasting. KLF15 is necessary for the suppression of SREBP-1 by GR, as demonstrated through experiments using KLF15 knockout mice. Additionally, we show that GR is involved in the fasting response, with heightened binding to the KLF15 enhancer. It has been widely known that the hypothalamic-pituitary-adrenal (HPA) axis regulates the secretion of glucocorticoids and plays a significant role in the metabolic response to undernutrition. These findings demonstrate the importance of the HPA-axis-regulated GR-KLF15 pathway in the regulation of lipid metabolism in the liver during fasting.

Metabolic engineering of Thermoanaerobacterium AK17 for increased ethanol production in seaweed hydrolysate

Sustainably produced renewable biomass has the potential to replace fossil-based feedstocks, for generation of biobased fuels and chemicals of industrial interest, in biorefineries. In this context, seaweeds contain a large fraction of carbohydrates that are a promising source for enzymatic and/or microbial biorefinery conversions. The thermoanaerobe Thermoanaerobacterium AK17 is a versatile fermentative bacterium producing ethanol, acetate and lactate from various sugars. In this study, strain AK17 was engineered for more efficient production of ethanol by knocking out the lactate and acetate side-product pathways. This was successfully achieved, but the strain reverted to acetate production by recruiting enzymes from the butyrate pathway. Subsequently this pathway was knocked out and the resultant strain AK17_M6 could produce ethanol close to the maximum theoretical yield (90%), leading to a 1.5-fold increase in production compared to the wild-type strain. Strain AK17 was also shown to successfully ferment brown seaweed hydrolysate from Laminaria digitata to ethanol in a comparatively high yield of 0.45 g/g substrate, with the primary carbon sources for the fermentations being mannitol, laminarin-derived glucose and short laminari-oligosaccharides. As strain AK17 was successfully engineered and has a wide carbohydrate utilization range that includes mannitol from brown seaweed, as well as hexoses and pentoses found in both seaweeds and lignocellulose, the new strain AK17_M6 obtained in this study is an interesting candidate for production of ethanol from both second and third generations biomass.

Antiglycation, antifibrillation and antioxidative effects of para coumaric acid and vitamin D; an in-vitro and in-silico comparative-cum-synergistic approach

Diabetes Mellitus is a metabolic disorder that results in impaired utilization of carbohydrates, lipids, and proteins. Severe hyperglycemia is its principal clinical symptom. Human serum albumin (HSA) is used as a model protein since it is viewed as a sign of glycaemic management because it is more likely to get glycated in diabetic people than other proteins. Para-coumaric acid (pCA), a phenolic acid, and Vitamin D (vit-D) are used as protective agents. In the present work, we deduce a synergistic-cum-comparative effect of pCA and vit-D, expecting some improvement in the efficacy of pCA when combined with vit-D. Methods employed are DPPH radical scavenging activity, In-vitro glycation of HSA, UV–vis spectroscopy, fluorescence analysis, and circular dichroism measurement. After treatment, increasein the absorbance and fluorescence intensity were reduced along with normalization of CD value. . The glycation-mediated fibrillation assessed by Congo-Red and Thioflavin T (ThT) were found to be diminishedwhen HSA was treated with equimolar concentration of p-CA and vit-D- treatment. Fructosamine adduct formation and lysine modificationwas also decreased, while inhibition to hemolysis and lipid peroxidation was found to increase upon treatment. The reactive oxygen species generation detection was also performed in lymphocytes treated with various protein samples. Docking results further confirmed theblocking some glycation-prone amino acids by both compounds. The study shows that the combination in the ratio of 1:1 has provided higher overall protection comparable to aminoguanidine (AG), the molecule which is utilized as a positive control.