Efficacy of the combination of Chinese herbal medicine and negative pressure wound therapy in the treatment of patients with diabetic foot ulcer: A meta-analysis.

This study aimed to systematically evaluate the clinical efficacy of Chinese herbal medicine combined with negative pressure wound therapy (NPWT) in the treatment of diabetic foot ulcers (DFU). Computerised searches of the China National Knowledge Infrastructure, Wanfang, Chinese BioMedical Literature Database, PubMed, Cochrane Library and Embase databases were conducted for randomised controlled trials on the use of Chinese herbal medicines combined with NPWT for the treatment of DFU. The search period ranged from the time of establishment of each database to July 2023. Literature screening and data extraction were performed independently by two investigators, and the quality of the included studies was assessed. The meta-analysis was performed using Review Manager 5.4 software. A total of 25 studies were analysed, including 1777 DFUs, with 890 and 887 patients in the experimental and control groups, respectively. The results showed that the treatment of DFUs with a Chinese herbal medicine in combination with NPWT increased the overall effectiveness (odds ratio [OR] = 4.32, 95% confidence interval [CI]: 2.96-6.30, p < 0.001), wound healing rate (mean difference [MD] = 18.35, 95% CI: 13.07-23.64, p < 0.001) and ankle brachial index (MD = 0.10, 95% CI: 0.06-0.14, p < 0.001); reduced the wound healing time (MD = -11.01, 95% CI: -13.25 to -8.78, p < 0.001) and post-treatment wound area (MD = -1.73, 95% CI: -2.46 to -1.01, p < 0.001); decreased the C-reactive protein level (MD = -3.57, 95% CI: -5.13 to -2.00, p < 0.001); and increased vascular endothelial growth factor level (MD = 19.20, 95% CI: 8.36-30.05, p < 0.001). Thus, Chinese herbal medicines combined with NPWT can effectively promote wound healing, reduce inflammation and shorten the disease course in patients with DFU, while demonstrating precise clinical efficacy.

The Role of Iron Overload in Diabetic Cognitive Impairment: A Review.

It is well documented that diabetes mellitus (DM) is strongly associated with cognitive decline and structural damage to the brain. Cognitive deficits appear early in DM and continue to worsen as the disease progresses, possibly due to different underlying mechanisms. Normal iron metabolism is necessary to maintain normal physiological functions of the brain, but iron deposition is one of the causes of some neurodegenerative diseases. Increasing evidence shows that iron overload not only increases the risk of DM, but also contributes to the development of cognitive impairment. The current review highlights the role of iron overload in diabetic cognitive impairment (DCI), including the specific location and regulation mechanism of iron deposition in the diabetic brain, the factors that trigger iron deposition, and the consequences of iron deposition. Finally, we also discuss possible therapies to improve DCI and brain iron deposition.

Systematic dissection of genomic features determining the vast diversity of conotoxins.

BACKGROUND: Conus, a highly diverse species of venomous predators, has attracted significant attention in neuroscience and new drug development due to their rich collection of neuroactive peptides called conotoxins. Recent advancements in transcriptome, proteome, and genome analyses have facilitated the identification of conotoxins within Conus' venom glands, providing insights into the genetic features and evolutionary patterns of conotoxin genes. However, the underlying mechanism behind the extraordinary hypervariability of conotoxins remains largely unknown. RESULTS: We analyzed the transcriptomes of 34 Conus species, examining various tissues such as the venom duct, venom bulb, and salivary gland, leading to the identification of conotoxin genes. Genetic variation analysis revealed that a subset of these genes (15.78% of the total) in Conus species underwent positive selection (Ka/Ks > 1, p < 0.01). Additionally, we reassembled and annotated the genome of C. betulinus, uncovering 221 conotoxin-encoding genes. These genes primarily consisted of three exons, with a significant portion showing high transcriptional activity in the venom ducts. Importantly, the flanking regions and adjacent introns of conotoxin genes exhibited a higher prevalence of transposon elements, suggesting their potential contribution to the extensive variability observed in conotoxins. Furthermore, we detected genome duplication in C. betulinus, which likely contributed to the expansion of conotoxin gene numbers. Interestingly, our study also provided evidence of introgression among Conus species, indicating that interspecies hybridization may have played a role in shaping the evolution of diverse conotoxin genes. CONCLUSIONS: This study highlights the impact of adaptive evolution and introgressive hybridization on the genetic diversity of conotoxin genes and the evolution of Conus. We also propose a hypothesis suggesting that transposable elements might significantly contribute to the remarkable diversity observed in conotoxins. These findings not only enhance our understanding of peptide genetic diversity but also present a novel approach for peptide bioengineering.

Utilization of lipidic food waste as low-cost nutrients for enhancing the potentiality of biofuel production from engineered diatom under temperature variations.

The scarcity of natural fossil fuels presents a promising opportunity for the development of renewable microalgae-based biofuels. However, the current microalgae cultivation is unable to effectively address the high costs of the production of biofuels. To tackle this challenge, this study focused on recruiting engineered Phaeodactylum tricornutum (FabG-OE) to enhance biomass accumulation and lipid production by employing food waste hydrolysate under temperature variations. The biomass and lipid accumulations of FabG-OE were improved effectively in mixed culture medium and food waste hydrolysate at a volume ratio (v/v) of 80:20 at 30 °C. It was found that oxidative stress might contribute to the overexpression of lipogenic genes, thereby leading to lipogenesis at 30 °C. Upscaling cultivation of FabG-OE at 30 °C using a semi-continuous strategy and batch strategy was conducted to achieve 0.73 and 0.77 g/L/d of biomass containing 0.35 and 0.38 g/L/d of lipid, respectively. In summary, these findings provide valuable insights for advancing microalgae-based biofuel production.

Attitudes and influencing factors associated with smoking cessation: An online cross-sectional survey in China.

INTRODUCTION: Quitting smoking, the critical path to reach the global targets of reducing tobacco use, can bring major and immediate health benefits to smokers. Exploring factors that help individuals to quit smoking is of great importance. The present study explored influencing factors on smoking cessation, in order to provide comprehensive reference for tobacco control policies. METHODS: Ex-smokers and current smokers were recruited online in this cross-sectional survey, from 1 October to 31 November 2022, in China. The observational data were collected using a questionnaire to collect information with respect to sociodemographic characteristics of smokers, attitudes towards smoking cessation, details of smoking cessation, and different potential factors related to smoking cessation through open-ended questions. RESULTS: A total of 638 smokers from 30 provinces were recruited as eligible respondents, with a mean age of 37.3 ± 11.7 years and a mean smoking history of 15.9 ± 13.7 years. The percentage of males was 92.3%. Of the 638 respondents, only 3.9% had no intention to stop smoking. Among 155 subjects who had quitted smoking successfully, willpower (55.5%) was considered as the most important contributing factor. Among 365 subjects who tried to quit but failed, lack of willpower (28.2%), tobacco dependence (16.2%), influence of surrounding smokers or smoking environments (15.9%), bad moods (9.9%), stress from work or life (7.9%), habits (7.1%), socialization (4.1%), and easy availability of tobacco (2.7%) were considered as the adverse factors leading to failure in quitting smoking. CONCLUSIONS: Willpower and support from family members were the vital factors that lead to successful smoking cessation. Future tobacco control policies should also focus on addressing withdrawal symptoms and creating smoke-free environments as well as other factors.

Effects of liraglutide on astrocyte polarization and neuroinflammation in db/db mice: focus on iron overload and oxidative stress.

Neuroinflammation plays a crucial role in the occurrence and development of cognitive impairment in type 2 diabetes mellitus (T2DM), but the specific injury mechanism is not fully understood. Astrocyte polarization has attracted new attention and has been shown to be directly and indirectly involved in neuroinflammation. Liraglutide has been shown to have beneficial effects on neurons and astrocytes. However, the specific protection mechanism still needs to be clarified. In this study, we assessed the levels of neuroinflammation and A1/A2-responsive astrocytes in the hippocampus of db/db mice and examined their relationships with iron overload and oxidative stress. First, in db/db mice, liraglutide alleviated the disturbance of glucose and lipid metabolism, increased the postsynaptic density, regulated the expression of NeuN and BDNF, and partially restored impaired cognitive function. Second, liraglutide upregulated the expression of S100A10 and downregulated the expression of GFAP and C3, and decreased the secretion of IL-1ß, IL-18, and TNF-α, which may confirm that it regulates the proliferation of reactive astrocytes and A1/A2 phenotypes polarize and attenuate neuroinflammation. In addition, liraglutide reduced iron deposition in the hippocampus by reducing the expression of TfR1 and DMT1 and increasing the expression of FPN1; at the same time, liraglutide by up-regulating the levels of SOD, GSH, and SOD2 expression, as well as downregulation of MDA levels and NOX2 and NOX4 expression to reduce oxidative stress and lipid peroxidation. The above may attenuate A1 astrocyte activation. This study preliminarily explored the effect of liraglutide on the activation of different astrocyte phenotypes and neuroinflammation in the hippocampus of a T2DM model and further revealed its intervention effect on cognitive impairment in diabetes. Focusing on the pathological consequences of astrocytes may have important implications for the treatment of diabetic cognitive impairment.

Bioremediation of Catechol and Concurrent Accumulation of Biocompounds by the Microalga Crypthecodinium cohnii.

Burgeoning commercial applications of catechol have led to its excessive accumulation in the environment, thereby posing a severe ecological threat. Bioremediation has emerged as a promising solution. The potential of the microalga Crypthecodinium cohnii to degrade catechol and use the byproduct as a carbon source was investigated in this study. Catechol significantly increased C. cohnii growth and was rapidly catabolized within 60 h of cultivation. Transcriptomic analysis highlighted the key genes involved in catechol degradation. Real-time polymerase chain reaction (RT-PCR) analysis showed that transcription of key genes CatA, CatB, and SaID involved in the ortho-cleavage pathway was remarkably increased by 2.9-, 4.2-, and 2.4- fold, respectively. Key primary metabolite content was also markedly altered, with a specific increment in polyunsaturated fatty acids. Electron microscopy and antioxidant analysis showed that C. cohnii could tolerate catechol treatment without morphological aberrations or oxidative stress. The findings provide a strategy for C. cohnii in the bioremediation of catechol and concurrent polyunsaturated fatty acids (PUFA) accumulation.

Metabolic engineering and pathway construction for O-acetyl-L-homoserine production in Escherichia coli.

O-Acetyl-L-homoserine (OAH) is a potentially important platform metabolic intermediate for the production of homoserine lactone, methionine, 1,4-butanediol and 1,3-propanediol which have giant market value. Currently, multiple strategies have been adopted to explore sustainable production of OAH. However, the production of OAH by consuming cheap bio-based feedstocks with Escherichia coli as the chassis is still in its infancy. Construction of high yield OAH-producing strains is of great significance in industry. In this study, we introduced an exogenous metA from Bacillus cereus (metXbc) and engineered an OAH-producing strain by combinatorial metabolic engineering. Initially, exogenous metXs/metA were screened and used to reconstruct an initial biosynthesis pathway of OAH in E. coli. Subsequently, the disruption of degradation and competitive pathways combined with optimal expression of metXbc were carried out, accumulating 5.47 g/L OAH. Meanwhile, the homoserine pool was enriched by overexpressing metL with producing 7.42 g/L OAH. Lastly, the carbon flux of central carbon metabolism was redistributed to balance the metabolic flux of homoserine and acetyl coenzyme A (acetyl-CoA) in OAH biosynthesis with accumulating 8.29 g/L OAH. The engineered strain produced 24.33 g/L OAH with a yield of 0.23 g/g glucose in fed-batch fermentation. By these strategies, the key nodes for OAH synthesis were clarified and corresponding strategies were proposed. This study would lay a foundation for OAH bioproduction. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03564-5.

Ecotoxicological risk of antibiotics and their mixtures to aquatic biota with the DGT technique in sediments.

Antibiotics are emerging contaminants and widely used in human healthcare, livestock, and aquaculture. The toxicity posed by antibiotics and their mixtures in sediments depends on their bioavailability. Now, the bioavailability of organic materials can be determined accurately by the diffusive gradients in thin films (DGT) technique. This technique was used for the first time ever in this study to evaluate in detail the integral toxicity of antibiotics in sediments to aquatic biota. Zhelin Bay was selected as a case study, because it is the largest mariculture area in eastern Guangdong, South China. Two antibiotics, chlortetracycline (CTC) (A) and sulfachlorpyridazine (SCP), were detected at average concentrations of 2.83 and 1.14 ng/ml, respectively. The other fifteen antibiotics were undetectable. The single risk assessment based on the risk quotient (RQ) of CTC and SCP shows that a relatively low risk has occurred. After this careful assessment of probabilistic ecotoxicological risks, the combined toxicity of antibiotic mixtures (CTC and SCP) clearly indicates that the toxicity probability of surface sediments to aquatic organisms was relatively low (0.23%).

Application of diffusive gradients in thin films to determine rare earth elements in surface sediments of Daya Bay, China: Occurrence, distribution and ecotoxicological risks.

Known as burgeoning contaminants, the bioavailability of rare earth elements (REEs) can be determined using diffusive gradients in thin films (DGT). As Daya Bay (South China) has been under serious anthropogenic influences, the present study examined the distribution of REEs in surface sediments and their possible ecological risks in the bay. The range of DGT-labile concentrations of REEs (∑REEs) was from 5.67 µg/L to 8.41 µg/L, with an average of 7.34 µg/L. Results of assessment of single REE toxicity revealed that the risk quotient (RQ) values of Y, Ce and Yb were >1, indicating that their potential negative impacts on the nearby environment. However, analysis of the integral toxicity of REE mixtures through assessment of probabilistic ecotoxicological risks showed that there was a negligibly low probability of toxicity of PRE surface sediments to aquatic organisms in the study area.

Rerouting Fluxes of the Central Carbon Metabolism and Relieving Mechanism-Based Inactivation of l-Aspartate-α-decarboxylase for Fermentative Production of ß-Alanine in Escherichia coli.

ß-Alanine, with the amino group at the ß-position, is an important platform chemical that has been widely applied in pharmaceuticals and feed and food additives. However, the current modest titer and productivity, increased fermentation cost, and complicated operation are the challenges for producing ß-alanine by microbial fermentation. In this study, a high-yield ß-alanine-producing strain was constructed by combining metabolic engineering, protein engineering, and fed-batch bioprocess optimization strategies. First, an aspartate-α-decarboxylase from Bacillus subtilis was introduced in Escherichia coli W3110 to construct an initial ß-alanine-producing strain. Production of ß-alanine was obviously increased to 4.36 g/L via improving the metabolic flux and reducing carbon loss by rerouting fluxes of the central carbon metabolism. To further increase ß-alanine production, mechanism-based inactivation of aspartate-α-decarboxylase was relieved by rational design to maintain the productivity at a high level in ß-alanine fed-batch fermentation. Finally, fed-batch bioprocess optimization strategies were used to improve ß-alanine production to 85.18 g/L with 0.24 g/g glucose yield and 1.05 g/L/h productivity in fed-batch fermentation. These strategies can be effectively used in the construction of engineered strains for ß-alanine and production of its derivatives, and the final engineered strain was a valuable microbial cell factory that can be used for the industrial production of ß-alanine.

Liraglutide Alleviates Cognitive Deficit in db/db Mice: Involvement in Oxidative Stress, Iron Overload, and Ferroptosis.

Studies have shown that diabetes is associated with the occurrence of neurodegenerative diseases and cognitive decline. However, there is currently no effective treatment for diabetes-induced cognitive dysfunction. The superior efficacy of liraglutide (LIRA) for cognitive impairment and numerous neurodegenerative diseases has been widely demonstrated. This study determined the effects of LIRA on diabetic cognitive impairment and on the levels of oxidative stress, lipid peroxidation, iron metabolism and ferroptosis in the hippocampus. Mice were injected daily with liraglutide (200 µg/kg/d) for 5 weeks. LIRA could repair damaged neurons and synapses, and it increased the protein expression levels of PSD 95, SYN, and BDNF. Furthermore, LIRA significantly decreased oxidative stress and lipid peroxidation levels by downregulating the production of ROS and MDA and upregulating SOD and GSH-Px in the serum and hippocampus, and the upregulation of SOD2 expression was also proven. The decreased levels of TfR1 and the upregulation of FPN1 and FTH proteins observed in the LIRA-treated db/db group were shown to reduce iron overload in the hippocampus, whereas the increased expression of Mtft and decreased expression of Mfrn in the mitochondria indicated that mitochondrial iron overload was ameliorated. Finally, LIRA was shown to prevent ferroptosis in the hippocampus by elevating the expression of GPX4 and SLC7A11 and suppressing the excessive amount of ACSL4; simultaneously, the damage to the mitochondria observed by TEM was also repaired. For the first time, we proved in the T2DM model that ferroptosis occurs in the hippocampus, which may play a role in diabetic cognitive impairment. LIRA can reduce oxidative stress, lipid peroxidation and iron overload in diabetic cognitive disorders and further inhibit ferroptosis, thereby weakening the damage to hippocampal neurons and synaptic plasticity and ultimately restoring cognitive function.

FMNL1 Exhibits Pro-Metastatic Activity via CXCR2 in Clear Cell Renal Cell Carcinoma.

Formin-like (FMNL) proteins are responsible for cytoskeletal remodeling and have been implicated in the progression and spread of human cancers. Yet the clinical significance and biological function of FMNL1 in clear cell renal cell carcinoma (ccRCC) remain unclear. In this study, the expression of FMNL1 in ccRCC and its clinical value were determined by tissue microarray-based IHC and statistical analyses. The role of FMNL1 in ccRCC metastasis and the underlying mechanism were investigated via in vitro and in vivo models using gene regulation detection, ChIP, Luciferase reporter assays, and rescue experiments. We show that FMNL1 is upregulated in ccRCC and exhibits pro-metastatic activity via induction of CXCR2. High expression of FMNL1 is significantly correlated with advanced tumor stage, higher pathological tumor grade, tumor metastasis, and unfavorable prognosis in two independent cohorts containing over 800 patients with ccRCC. The upregulation of FMNL1 in ccRCC is mediated by the loss of GATA3. Ectopic expression of FMNL1 promotes, whereas FMNL1 depletion inhibits cell migration in vitro and tumor metastasis in vivo. The FMNL1-enhanced cell mobility is markedly attenuated by the knockdown of CXCR2. Further studies demonstrate that FMNL1 increases the expression of CXCR2 via HDAC1. In clinical samples, FMNL1 expression is positively associated with CXCR2, and is negatively connected to GATA3 expression. Collectively, our data suggest FMNL1 serve as a potential prognostic factor and function as an oncogene. The axis of GATA3/FMNL1/CXCR2 may present a promising therapeutic target for tumor metastasis in ccRCC.

Expression, Affinity, and Functional Characterization of the Specific Binding of Two Putative Pheromone-Binding Proteins in the Omnivorous German Cockroach Blattella germanica.

The German cockroach Blattella germanica (L.) is an important pest in medical, veterinary, and public health. Studies on the olfaction mechanism of hemimetabolous insects have rarely been reported, especially in cockroaches. Pheromone-binding proteins (PBPs) play a vital role in insect sex pheromone recognition, which solubilize and carry the hydrophobic pheromonal compounds through the antennal lymph to receptors. In this study, two potential PBPs (BgerOBP26 and BgerOBP40) were identified on the basis of their biased expression in male antennae using tissue transcriptome data and verified by the quantitative real-time polymerase chain reaction approach. We then expressed and purified the two identified odorant-binding proteins (OBPs) using the Escherichia coli expression system and affinity purification. In vitro binding studies showed that the two OBPs display stronger binding affinities to the female volatile sex pheromone blattellaquinone than to its analogues and contact sex pheromone components. Finally, three-dimensional modeling of the two OBPs and dock conformation with sex pheromone molecules showed BgerOBP26 has a larger odorant cavity and more conservative active amino acid residues than BgerOBP40. These results illuminated the binding characteristics of potential PBPs of B. germanica, which could lay the groundwork for improved understanding of many aspects of the chemical ecology of B. germanica. Moreover, this information complements the understanding of the olfactory molecular mechanism in cockroaches and provides potential gene targets for B. germanica control.

A novel method for in situ visualization of the growth kinetics, structures and behaviours of gas-phase fabricated metallic alloy nanoparticles.

Modulation of gas-phase nanoparticles is unmethodical as there is a lack of information on the growth kinetics and its determinants. Here, we developed a novel in situ evaporation-and-deposition (EAD) method inside a transmission electron microscope which enables direct visualization of the nucleation, growth, coalescence and shape/phase evolution of gas-phase fabricated nanoparticles. Using a Bi49Pb18Sn12In21 alloy as a sample, the critical factors that determine the feasibility of this EAD method are revealed. By direct observation, it is unambiguously evidenced that pristine nanoparticles with ultra-clean surfaces are extremely energetic during growth. Coalescence between EAD-fabricated nanoparticles takes place in a manner beyond conventional understanding acquired by postmortem analyses. Moreover, the EAD-fabricated diverse nanoparticles show distinct size distributions and sandwich-type or Janus-type phase segregations. These features offer an effective tool to identify atomic surface steps of thin films and can provide an ideal case for exploring the phase diagrams of nanoalloys in the future.

Longitudinal follow-up study of the retrobulbar and intrarenal hemodynamics in patients with T2DM.

OBJECTIVE: The primary aim of this study is to examine the hemodynamics of retrobulbar and intrarenal in the changes of early stage of type 2 diabetes mellitus (T2DM) patients from 2000 to 2015 and to assess incidence associated with diabetic kidney disease (DKD) and diabetic retinopathy (DR). METHOD: Our study contained 60 subjects newly diagnosed of T2DM were divided into 2 groups base on the mean resistive index (RI) (≤0.7 and >0.7) of hemodynamic and to compare between-group differences of the early changes in hemodynamics of retrobulbar and intrarenal and also to conclude the incidences of diabetic kidney disease (DKD) and diabetic retinopathy (DR)subsequently with a long follow-up duration(2000-2015). First, to compare the mean RI of central retinal artery (CRA) between 2 groups. Second, to compare the mean RI of intrarenal hemodynamics in the bilateral interlobular renal arteries, renal function parameters (blood urea nitrogen (BUN), creatinine (Cr), blood glucose parameters (glycosylated hemoglobinA1c (HbA1c), fasting plasma glucose (FBG), and 2-hour postprandial blood glucose (2hPBG)), glomerular filtration rate (GFR), albumin excretion rate (AER), and urine albumin-to-creatinine ratio (UACR) between 2 groups. RESULTS: First part of our follow-up studies was to compare hemodynamic RI index of retrobulbar in years of 2000 and 2015, both renal function and blood glucose parameters were fund significantly enhanced in subject group RIs ≤0.7. Incidence of DKD and DR was notably lower in group RIs ≤0.7 than group RIs > 0.7, difference was statistically significant (P < .05). Incidence of HbA1c ≤7% was higher in group RIs ≤0.7 than group RIs >0.7, but difference was not statistically significant (P > .05). Incidence of proliferative diabetic retinopathy (PDR) was notably lower in group RIs ≤0.7 than group RIs >0.7, but the difference was not statistically significant (P > .05). Second part of our follow-up studies was to compare hemodynamic RI index of interlobular renal in years of 2000 and 2015, both renal function and blood glucose parameters were fund significantly enhanced in subject group RIs ≤0.7. Compared data of various incidences from first part of study were coherent with second part. (Incidence of DKD and DR was notably lower in group RIs ≤0.7 than group RIs >0.7, difference was statistically significant (P < .05). Incidence of HbA1c ≤7% was higher in group RIs ≤0.7 than group RIs >0.7, but difference was not statistically significant (P > .05). Incidence of PDR was notably lower in group RIs ≤0.7 than group RIs >0.7, but the difference was not statistically significant (P > .05). CONCLUSIONS: RIs of retrobulbar and interlobular renal which would serve as a good predictors for the hemodynamics changes in retrobulbar and intrarenal would assess incidence of DKD and DR during the preclinical stage in long-term range excluding renal function and HbA1c in T2DM patients.

Association between KITLG Gene Polymorphisms and Testicular Germ Cell Tumors: A Systematic Review and Meta-analysis.

It has been reported that c-KIT ligand (KITLG) gene polymorphisms may be associated with testicular germ cell tumors (TGCT). Owing to mixed and inconclusive results, we conducted a systematic review and meta-analysis to summarize and clarify this association. A systematic search of studies on the association between KITLG gene polymorphisms and TGCT susceptibility was conducted in databases. Odds ratios and 95% confidence intervals were used to pool the effect size. Six articles were included in our systematic review and meta-analysis. Compared with adenine (A), KITLG rs995030 guanine (G) might be associated with increased risk of TGCT. There are insufficient data to fully confirm the association between KITLG rs4474514 and TGCT susceptibility. Well-designed studies with larger sample size and more subgroups are required to validate the risk identified in the current meta-analysis.

Transcriptional regulation of microalgae for concurrent lipid overproduction and secretion.

Commercialization of algal lipids and biofuels is still impractical owing to the unavailability of lipogenic strains and lack of economically viable oil extraction strategies. Because lipogenesis is governed by multiple factors, success in generating industrial-suitable algal strains using conventional strategies has been limited. We report the discovery of a novel bZIP1 transcription factor, NobZIP1, whose overexpression results in a remarkable elevation of lipid accumulation and lipid secretion in a model microalga Nannochloropsis oceanica, without impairing other physiological properties. Chromatin immunoprecipitation-quantitative PCR analysis revealed that the key genes up- and down-regulated by NobZIP1 are involved in lipogenesis and cell wall polymer synthesis, respectively, which, in turn, induce lipid overproduction and secretion. Among these regulated genes, UDP-glucose dehydrogenase was shown to alter cell wall composition, thus also boosting lipid secretion. In summary, these results offer a comprehensive strategy for concurrent lipid overproduction and secretion, strongly increasing the commercial potential of microalgae.

Overproduction of Bioactive Algal Chrysolaminarin by the Critical Carbon Flux Regulator Phosphoglucomutase.

Chrysolaminarin, the primary polysaccharide reservoir in some marine algae, has attracted much attention due to its broad health properties. However, its biosynthetic pathway and regulation mechanisms have rarely been reported which hinders the improvement of production efficiency. Therefore, this study aims to identify key metabolic nodes in the chrysolaminarin biosynthetic pathway. A phosphoglucomutase (PGM) in the model microalga Phaeodactylum tricornutum, revealing its critical role in chrysolaminarin biosynthesis is identified. PGM overexpression significantly elevates chrysolaminarin content by 2.54-fold and reaches 25.6% of cell dry weight; while algal growth and photosynthesis are not impaired. Besides, PGM overexpression up- and down-regulates the expression of chrysolaminarin and lipid biosynthetic genes, respectively. Microscopic analysis of aniline blue stained cells reveals that overproduced chrysolaminarin localized predominantly in vacuoles. Lipidomic analyses reveal that PGM overexpression significantly reduces the lipid content. The findings reveal the critical role of PGM in regulating the carbon flux between carbohydrate and lipid biosynthesis in microalgae, and provide a promising candidate for high efficiency production of chrysolaminarin.

Effects of macrophyte cultivation on community structure of rotifer in small lakes.

To understand the effects of macrophyte growth on water environment and rotifer community structure, monthly survey lasted for one year from October 2015 to September 2016 was conducted in Lake Minghu and Lake Nanhu at Jinan University in Guangzhou. There was no macrophyte cultivation in Lake Minghu. A kind of macrophyte Hydrilla verticillata grows from March-October in Lake Nanhu and grows vigorously in June-September. In this study, 50 species belonging to 23 gene-ra of rotifer, were recorded in the two lakes. 32 species were found in Lake Minghu and 39 species in Lake Nanhu, respectively. The dominant species in Lake Minghu were Polyarthra vulgaris, Trichocerca pusilla and Liliferotrocha subtilis. The dominant species in Lake Nanhu were Keratella cochlearis, Colurella adriatica and Lecane (Monostyla) bulla. The highest abundance of rotifers in Lake Minghu was at 3790 ind·L-1 in October 2015, and the lowest at 854 ind·L-1 in March 2016. The highest abundance of rotifers in Lake Nanhu was at 3555 ind·L-1 in November 2015, and the lowest at 977 ind·L-1 in January 2016. Results from the ANOSIM (one-way) test revealed that the community structure of rotifers was significantly different between Lake Minghu and Lake Nanhu. The largest contribution rate of the difference between the two lakes was made by Keratella cochlearis and Polyarthra vulgaris. RDA analysis showed that total phosphorus, chlorophyll a, and water temperature had significant impacts on the community structure of rotifer in Lake Minghu. During the period with luxuriant macrophyte in Lake Nanhu, the rotifer community structure was most influenced by total phosphorus, water temperature, chlorophyll a and water depth, dominated by benthic species Squatinella mutica, Colurella adriatica and Lecane bulla. During the period with sparse macrophyte, the community was mainly influenced by total nitrogen and transparency, dominanted by planktonic species Polyarthra vulgaris and Trichocerca similis. During the period with no macrophyte, communities were mainly influenced by pH and dissolved oxygen, and also dominated by planktonic ones Polyarthra vulgaris and Anuraeopsis fissa. Macrophyte could effectively absorb nutrients in water, inhibit growth of phytoplankton, improve water quality, increase spatial heterogeneity, support more species of rotifer, and maintain a stable aquatic ecosystem.