The genetic basis and process of inbreeding depression in an elite hybrid rice.

Inbreeding depression refers to the reduced performance arising from increased homozygosity, a phenomenon that is the reverse of heterosis and exists among plants and animals. As a natural self-pollinated crop with strong heterosis, the mechanism of inbreeding depression in rice is largely unknown. To understand the genetic basis of inbreeding depression, we constructed a successive inbreeding population from the F2 to F4 generation and observed inbreeding depression of all heterotic traits in the progeny along with the decay of heterozygosity in each generation. The expected depression effect was largely explained by 13 QTLs showing dominant effects for spikelets per panicle, 11 for primary branches, and 12 for secondary branches, and these loci constitute the main correlation between heterosis and inbreeding depression. However, the genetic basis of inbreeding depression is also distinct from that of heterosis, such that a biased transmission ratio of alleles for QTLs with either dominant or additive effects in four segregation distortion regions would result in minor effects in expected depression. Noticeably, two-locus interactions may change the extent and direction of the depression effects of the target loci, and overall interactions would promote inbreeding depression among generations. Using an F2:3 variation population, the actual performance of the loci showing expected depression was evaluated considering the heterozygosity decay in the background after inbreeding. We found inconsistent or various degrees of background depression from the F2 to F3 generation assuming different genotypes of the target locus, which may affect the actual depression effect of the locus due to epistasis. The results suggest that the genetic architecture of inbreeding depression and heterosis is closely linked but also differs in their intrinsic mechanisms, which expand our understanding of the whole-genome architecture of inbreeding depression.

Effect of Dexmedetomidine on Intraoperative Hemodynamics and Blood Loss in Patients Undergoing Spine Surgery: A Systematic Review and Meta-Analysis.

Objective Dexmedetomidine (Dex) is a highly selective α2 adrenoceptor agonist that reduces blood pressure and heart rate. However, its ability to provide stable hemodynamics and a clinically significant reduction in blood loss in spine surgery is still a matter of debate. This study aimed to investigate the effects of Dex on intraoperative hemodynamics and blood loss in patients undergoing spine surgery.Methods The Web of Science, MEDLINE, EMBASE, and the Cochrane Library were searched up to February 2023 for randomized controlled trials (RCTs) including patients undergoing spine surgeries under general anaesthesia and comparing Dex and saline. A fixed- or random-effect model was used depending on heterogeneity.Results Twenty-one RCTs, including 1388 patients, were identified. Dex added the overall risk of intraoperative hypotension (odds ratio [OR]: 2.11; 95% confidence interval [CI]: 1.24 - 3.58; P=0.006) and bradycardia (OR: 2.48; 95%CI: 1.57 - 3.93; P=0.0001). The use of a loading dose of Dex led to significantly increased risks of intraoperative hypotension (OR: 2.00; 95%CI: 1.06 - 3.79; P=0.03) and bradycardia (OR: 2.28; 95%CI: 1.42 - 3.66; P=0.0007). For patients receiving total intravenous anesthesia, there was an increased risk of hypotension (OR: 2.90; 95%CI: 1.24 - 6.82; P=0.01) and bradycardia (OR: 2.66; 95%CI: 1.53 - 4.61; P=0. 0005). For patients in the inhalation anesthesia group, only an increased risk of bradycardia (OR: 4.95; 95%CI: 1.41 - 17.37; P=0.01) was observed. No significant increase in the risk of hypotension and bradycardia was found in the combined intravenous-inhalation anesthesia group. The incidence of severe hypotension (OR: 2.57; 95%CI: 1.05 - 6.32; P=0.04), but not mild hypotension, was increased. Both mild (OR: 2.55; 95%CI: 1.06 - 6.15; P=0.04) and severe (OR: 2.45; 95%CI: 1.43 - 4.20; P=0.001) bradycardia were associated with a higher risk. The overall analyses did not reveal significant reduction in intraoperative blood loss. However, a significant decrease in blood loss was observed in total inhalation anesthesia subgroup (mean difference [MD]: -82.97; 95%CI: -109.04 - -56.90; P<0.001).Conclusions Dex increases the risks of intraoperative hypotension and bradycardia in major spine surgery. The administration of a loading dose of Dex and the utilization of various anesthesia maintenance methods may potentially impact hemodynamic stability and intraoperative blood loss.

Improved Water Collection from Short-Term Fog on a Patterned Surface with Interconnected Microchannels.

Fog harvesting is considered a promising freshwater collection strategy for overcoming water scarcity, because of its environmental friendliness and strong sustainability. Typically, fogging occurs briefly at night and in the early morning in most arid and semiarid regions. However, studies on water collection from short-term fog are scarce. Herein, we developed a patterned surface with highly hydrophilic interconnected microchannels on a superhydrophobic surface to improve droplet convergence driven by the Young-Laplace pressure difference. With a rationally designed surface structure, the optimized water collection rate from mild fog could reach up to 67.31 g m-2 h-1 (6.731 mg cm-2 h-1) in 6 h; this value was over 130% higher than that observed on the pristine surface. The patterned surface with interconnected microchannels significantly shortened the startup time, which was counted from the fog contact to the first droplet falling from the fog-harvesting surface. The patterned surface was also facilely prepared via a controllable strategy combining laser ablation and chemical vapor deposition. The results obtained in outdoor environments indicate that the rationally designed surface has the potential for short-term fog harvesting. This work can be considered as a meaningful attempt to address the practical issues encountered in fog-harvesting research.

Defects in phospholipase C zeta cause polyspermy and low fertilization after conventional IVF: not just ICSI failure.

ABSTRACT: Phospholipase C zeta (PLCζ) is a key sperm-borne oocyte-activating factor that triggers Ca2+ oscillations and the subsequent block to polyspermy following gamete fusion. Mutations in PLCZ1, the gene encoding PLCζ, cause male infertility and intracytoplasmic sperm injection (ICSI) fertilization failure; and PLCζ expression and localization patterns are significantly correlated with ICSI fertilization rate (FR). However, in conventional in vitro fertilization (cIVF), whether and how sperm PLCζ affects fertilization remain unclear. Herein, we identified one previously reported and two novel PLCZ1 mutations associated with polyspermy in vitro that are characterized by excessive sperm-zona binding and a delay in pronuclei (PN) formation. Immunofluorescence staining and oocyte activation testing revealed that virtually all spermatozoa from patients lacked functional PLCζ and were thus unable to evoke Ca2+ oscillations. ICSI with an artificial oocyte activation treatment successfully rescued the polyspermic phenotype and resulted in a live birth. Furthermore, we analyzed PLCζ in an additional 58 males after cIVF treatment in the Reproductive and Genetic Hospital of CITIC-Xiangya (Changsha, China) between February 2019 and January 2022. We found that the proportion of spermatozoa that expressed PLCζ was positively correlated with both 2PN rate and total FR. The optimal cutoff value below which males were likely to experience low FR (total FR ≤30%) after cIVF was 56.7% for the proportion of spermatozoa expressing PLCζ. Our study expands the mutation and the phenotypic spectrum of PLCZ1 and further suggests that PLCζ constitutes a promising biomarker for identifying low FRs cases in cIVF due to sperm-related oocyte activation deficiency and that sperm PLCζ analysis may benefit the wider male population and not only men with ICSI failure.

Fermentation of Ganoderma lucidum and Raphani Semen with a probiotic mixture attenuates cyclophosphamide-induced immunosuppression through microbiota-dependent or -independent regulation of intestinal mucosal barrier and immune responses.

BACKGROUND: Probiotic fermentation is a promising strategy for improving the nutritional and functional properties of traditional Chinese medicines (TCMs). Ganoderma lucidum and Raphani Semen are famous TCMs that have been shown to help alleviate immune system disorders. However, few studies have experimentally investigated the effects of probiotic-fermented G.lucidum and Raphani Semen on the immune system. PURPOSE: We established the in vitro fermentation of G. lucidum and Raphani Semen with a probiotic mixture (Bifidobacterium longum, Lactobacillus acidophilus, and l. fermentum) (GRFB), investigated its ameliorating effect against cyclophosphamide (CTX)-induced immunosuppression, and explored its possible mechanisms. METHODS: First, the different components in GRFB were identified by high-performance liquid chromatography. Second, its immune-stimulatory activities were evaluated in CTX-treated mice. Lastly, its possible in vitro and in vivo mechanisms were studied. RESULTS: Probiotic fermentation of G. lucidum and Raphani Semen altered some of its chemical constituents, potentially helping improve the ability of GRFB to alleviate immunosuppression. As expected, GRFB effectively ameliorated CTX-induced immunosuppression by increasing the number of splenic lymphocytes and regulating the secretion of serum and ileum cytokines. GRFB supplementation also effectively improved intestinal integrity in CTX-treated mice by upregulating tight junction proteins. It also protects against CTX-induced intestinal dysbiosis by increasing the abundance of beneficial bacteria and reducing the abundance of harmful bacteria. GRFB could directly promote intestinal immunity but not systemic immunity in vitro, suggesting a microbiota-dependent regulation of GRFB. Interestingly, cohousing CTX-induced immunosuppressed mice with GRFB-treated mice promoted their symptoms recovery. Enhanced CTX-induced immunosuppression by GRFB in vitro depended on the gut microbiota. Remarkably, a Kyoto Encyclopedia of Genes and Genomes analysis showed that the GRFB-reprogrammed microbiota was significantly enriched in DNA damage repair pathways, which contribute to repairing the intestinal mucosal barrier. CONCLUSION: This is the first study to suggest that compare with unfermented G. lucidum and Raphani Semen, GRFB can more effectively promote intestinal immunity and manipulate the gut microbiota to promote immunostimulatory activity and repair immunosuppression-induced intestinal barrier damage by biotransforming G.lucidum and Raphani Semen components.

Chemically Recyclable Biobased Non-Isocyanate Polyurethane Networks from CO2 -Derived Six-membered Cyclic Carbonates.

Non-isocyanate polyurethanes (NIPUs) are widely studied as sustainability potential, because they can be prepared without using toxic isocyanates in the synthesis process. The aminolysis of cyclic carbonate to form NIPUs is a promising route. In this work, a series of NIPUs is prepared from renewable bis(6-membered cyclic carbonates) (iEbcc) and amines. The resulting NIPUs possess excellent mechanical properties and thermal stability. The NIPUs can be remolded via transcarbamoylation reactions, and iEbcc-TAEA-10 (the molar ratio of tris(2-aminoethyl)amine in amines is 10%) still get a recovery ratio of 90% in tensile stress after three cycles of remolding. In addition, the obtained materials can be chemically degraded into bi(1,3-diol) precursors with high purity (>99%) and yield (>90%) through alcoholysis. Meanwhile, the degraded products can be used to regenerate NIPUs with similar structures and properties as the original samples. The synthetic strategy, isocyanate-free and employing isoeugenol and carbon dioxide (CO2 ) as building blocks, makes this approach an attractive pathway to NIPU networks taking a step toward a circular economy.

Ribosome profiling reveals the translational landscape and allele-specific translational efficiency in rice.

Translational regulation is a critical step in the process of gene expression and governs the synthesis of proteins from mRNAs. Many studies have revealed translational regulation in plants in response to various environmental stimuli. However, there have been no studies documenting the comprehensive landscape of translational regulation and allele-specific translational efficiency in multiple plant tissues, especially those of rice, a main staple crop that feeds nearly half of the world's population. Here we used RNA sequencing and ribosome profiling data to analyze the transcriptome and translatome of an elite hybrid rice, Shanyou 63 (SY63), and its parental varieties Zhenshan 97 and Minghui 63. The results revealed that gene expression patterns varied more among tissues than among varieties at the transcriptional and translational levels. We identified 3392 upstream open reading frames (uORFs), and the uORF-containing genes were enriched in transcription factors. Only 668 of 13 492 long non-coding RNAs could be translated into peptides. Finally, we discovered numerous genes with allele-specific translational efficiency in SY63 and demonstrated that some cis-regulatory elements may contribute to allelic divergence in translational efficiency. Overall, these findings may improve our understanding of translational regulation in rice and provide information for molecular breeding research.

Simultaneous removal of COD and NH4+-N from domestic sewage by a single-stage up-flow anaerobic biological filter based on Feammox.

In recent years, Feammox has made it possible to remove NH4+-N under anaerobic conditions; however, its application in practical wastewater treatment processes has not been extensively reported. In this study, an up-flow anaerobic biological filter based on limonite (Lim-UAF) was developed to facilitate long-term and stable treatment of domestic sewage. Lim-UAF achieved the highest removal efficiency of chemical oxygen demand (COD) and NH4+-N at a hydraulic retention time (HRT) of 24 h (Stage II). Specifically, the COD and NH4+-N content decreased from 240.8 and 30.0 mg/L to about 7.5 and 0.35 mg/L, respectively. To analyze the potential nitrogen removal mechanism, the Lim-UAF was divided into three layers according to the height of the reactor. The results showed that COD and NH4+-N removal had remarkable characteristics in Lim-UAF. More than 55.0% of influent COD was removed in the lower layer (0-30 cm) of Lim-UAF, while 60.2% of NH4+-N was removed in the middle layer (30-60 cm). Microbial community analysis showed that the community structure in the middle and upper layers (60-90 cm) was relatively similar, but quite different from that of the lower layer. Heterotrophic bacteria were dominant in the lower layer, whereas iron-reducing and iron-oxidizing bacteria were enriched in the upper and middle layers. The formation of secondary minerals (siderite and Fe(OH)3) indicated that the Fe(III)/Fe(II) redox cycle occurred in Lim-UAF, which was triggered by the Feammox and NDFO processes. In summary, limonite was used to develop a single-stage wastewater treatment process for simultaneously removing organic matter and NH4+-N, which has excellent application prospects in domestic sewage treatment.

A Ghd7-centered regulatory network provides a mechanistic approximation to optimal heterosis in an elite rice hybrid.

Heterosis refers to the superior performance of hybrids over their parents, which is a general phenomenon occurring in diverse organisms. Many commercial hybrids produce high yield without delayed flowering, which we refer to as optimal heterosis and is desired in hybrid breeding. Here, we attempted to illustrate the genomic basis of optimal heterosis by reinvestigating the single-locus quantitative trait loci and digenic interactions of two traits, the number of spikelets per panicle (SP) and heading date (HD), using recombinant inbred lines and 'immortalized F2 s' derived from the elite rice (Oryza sativa) hybrid Shanyou 63. Our analysis revealed a regulatory network that may provide an approximation to the genetic constitution of the optimal heterosis observed in this hybrid. In this network, Ghd7 works as the core element, and three other genes, Ghd7.1, Hd1, and Hd3a/RFT1, also have major roles. The effects of positive dominance by Ghd7 and Ghd7.1 and negative dominance by Hd1 and Hd3a/RFT1 in the hybrid background contribute the major part to the high SP without delaying HD; numerous epistatic interactions, most of which involve Ghd7, also play important roles collectively. The results expand our understanding of the genic interaction networks underlying hybrid rice breeding programs, which may be very useful in future crop genetic improvement.

Temperature drives the assembly of Bacillus community in mangrove ecosystem.

Mangroves are located at the interface of terrestrial and marine environments, and experience fluctuating conditions, creating a need to better explore the relative role of the bacterial community. Bacillus has been reported to be the dominant group in the mangrove ecosystem and plays a key role in maintaining the biodiversity and function of the mangrove ecosystem. However, studies on bacterial and Bacillus community across four seasons in the mangrove ecosystem are scarce. Here, we employed seasonal large-scale sediment samples collected from the mangrove ecosystem in southeastern China and utilized 16S rRNA gene amplicon sequencing to reveal bacterial and Bacillus community structure changes across seasons. Compared with the whole bacterial community, we found that Bacillus community was greatly affected by season (temperature) rather than site. The key factors, NO3-N and NH4-N showed opposite interaction with superabundant taxa Bacillus taxa (SAT) and three rare Bacillus taxa including high rare taxa (HRT), moderate rare taxa (MRT) and low rare taxa (LRT). Network analysis suggested the co-occurrence of Bacillus community and Bacillus-bacteria, and revealed SAT had closer relationship compared with rare Bacillus taxa. HRT might act crucial response during the temperature decreasing process across seasons. This study fills a gap in addressing the assembly of Bacillus community and their role in maintaining microbial diversity and function in mangrove ecosystem.

Evansella halocellulosilytica sp. nov., an alkali-halotolerant and cellulose-dissolving bacterium isolated from bauxite residue.

An alkali and salt-tolerating strain FJAT-44876T was isolated from the bauxite residue sample. The 16S rRNA gene sequence and phylogenetic analysis suggest that strain FJAT-44876T was a member of the genus Evansella. It grew at 15-45 â„ƒ (optimum 20-25 â„ƒ) and pH 6.5-11.0 (optimum pH 8.0-9.0) with 0-20% (w/v) NaCl (optimum 6-8%). The major fatty acids were anteiso-C15:0, iso-C15:0, anteiso-C17:0, iso-C17:0, and C16:0. The cell wall peptidoglycan contained meso-diaminopimelic acid and MK-7 as the menaquinone. The major polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, and phosphatidylglycerol. The genomic DNA G+C content was 38.2%. The average nucleotide identity values between strain FJAT-44876T and closely related members were below the cutoff level for species delineation. Thus, based on the above results, strain FJAT-44876T represents a novel species of the genus Evansella, for which the name Evansella halocellulosilytica sp. nov., is proposed. The type strain is FJAT-44876T (=CCTCC AB 2016264T = DSM 104633T).

Neobacillus rhizophilus sp. nov. and Neobacillus citreus sp. nov., isolated from the citrus rhizosphere soil.

Two Gram-staining positive strains, FJAT-49825T and FJAT-50051T were isolated from a citrus rhizosphere soil sample. Strains FJAT-49825T and FJAT-50051T showed the highest 16S rRNA gene sequence similarity with the type strain of Neobacillus cucumis (98.4-98.5%). The 16S rRNA gene sequence similarity between strains FJAT-49825T and FJAT-50051T was 99.8%. Strain FJAT-49825T optimally grew at 35 °C, pH 6.0 in the absence of NaCl while strain FJAT-50051T grew at 40 °C, pH 7.0 and in presence of 2% NaCl (w/v). Both strains contained meso-2,6-diaminopimelic acid as the cell-wall diamino acid. The respiratory quinone of strains FJAT-49825T and FJAT-50051T was MK-7. The polar lipids of strain FJAT-49825T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified aminolipid and unidentified lipid whereas strain FJAT-50051T polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipid and unidentified lipid. The major fatty acids (> 10%) in both strains were iso-C15:0 and anteiso-C15:0. The genomic DNA G + C content of strains FJAT-49825T and FJAT-50051T were 40.8 and 41.1%, respectively. The average nucleotide identity and digital DNA-DNA hybridization value between strains FJAT-49825T and FJAT-50051T and with other members of the genus Neobacillus were lower than the cut-off value (95-96/70%) for interspecies identity. Based on the results, strains FJAT-49825T and FJAT-50051T represent two novel species of the genus Neobacillus, for which the names Neobacillus rhizophilus sp. nov. and Neobacillus citreus sp. nov. are proposed. The type strains are FJAT-49825T (= GDMCC 1.2592T = JCM 34834T) and FJAT-50051T (= GDMCC 1.2593T = JCM 34835T).

Lederbergia citri sp. nov., and Lederbergia citrisecundus sp. nov., isolated from citrus rhizosphere.

Two Gram-positive, rod-shaped, motile, endospore-forming strains, FJAT-49780T and FJAT-49732T were isolated from a citrus rhizosphere soil sample. The optimal growth temperatures for strains FJAT-49780T and FJAT-49732T were 45 and 35-40 °C, respectively. The optimal growth pH for strains FJAT-49732T and FJAT-49780T were pH 8.0 and pH 6.0, respectively. The 16S rRNA gene sequence similarity between FJAT-49780T and FJAT-49732T was 98.6%. Strains FJAT-49780T and FJAT-49732T shared 97.9-98.4% 16S rRNA gene sequence similarities to the type strain of Lederbergia wuyishanensis. In phylogenetic trees (based on 16S rRNA gene sequence), strains FJAT-49732T and FJAT-49780T clade with Lederbergia members. Both strains contained meso-diaminopimelic acid in their cell-wall peptidoglycan and MK-7 was the only isoprenoid quinone detected. The major fatty acids of strains FJAT-49732T and FJAT-49780T were anteiso-C15:0 and iso-C15:0. The polar lipids of strain FJAT-49780T were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid, unidentified phospholipid and unidentified lipids while strain FJAT-49732T contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified glycolipid, unidentified aminolipid and unidentified phospholipid. The genomic DNA G+C content of strains FJAT-49780T and FJAT-49732T were 37.0 and 36.7%, respectively. The digital DNA-DNA hybridization and average nucleotide identity values between strains FJAT-49780T and FJAT-49732T and with other members of the genus Lederbergia were below the cut-off level for species delineation. Thus, based on the above results, strains FJAT-49780T and FJAT-49732T represent two novel species of the genus Lederbergia, for which the names Lederbergia citri sp. nov., and Lederbergia citrisecundus sp. nov., are proposed. The type strains are FJAT-49780T (= CCTCC AB 2019242T = LMG 31583T) and FJAT-49732T (= CCTCC AB 2019246T = LMG 31584T).

Occurrence of antibiotics in waters, removal by microalgae-based systems, and their toxicological effects: A review.

Global antibiotics consumption has been on the rise, leading to increased antibiotics release into the environment, which threatens public health by selecting for antibiotic resistant bacteria and resistance genes, and may endanger the entire ecosystem by impairing primary production. Conventional bacteria-based treatment methods are only moderately effective in antibiotics removal, while abiotic approaches such as advanced oxidation and adsorption are costly and energy/chemical intensive, and may cause secondary pollution. Considered as a promising alternative, microalgae-based technology requires no extra chemical addition, and can realize tremendous CO2 mitigation accompanying growth related pollutants removal. Previous studies on microalgae-based antibiotics removal, however, focused more on the removal performances than on the removal mechanisms, and few studies have concerned the toxicity of antibiotics to microalgae during the treatment process. Yet understanding the removal mechanisms can be of great help for targeted microalgae-based antibiotics removal performances improvement. Moreover, most of the removal and toxicity studies were carried out using environment-irrelevant high concentrations of antibiotics, leading to reduced guidance for real-world situations. Integrating the two research fields can be helpful for both improving antibiotics removal and avoiding toxicological effects to primary producers by the residual pollutants. This study, therefore, aims to build a link connecting the occurrence of antibiotics in the aquatic environment, the removal of antibiotics by microalgae-based processes, and the toxicity of antibiotics to microalgae. Distribution of various categories of antibiotics in different water environments were summarized, together with the antibiotics removal mechanisms and performances in microalgae-based systems, and the toxicological mechanisms and toxicity of antibiotics to microalgae after either short-term or long-term exposure. Current research gaps and future prospects were also analyzed. The review could provide much valuable information to the related fields, and provoke interesting thoughts on integrating microalgae-based antibiotics removal research and toxicity research on the basis of environmentally relevant concentrations.

Kinetic modeling and process analysis for photo-production of ß-carotene in Dunaliella salina.

Dunaliella salina is a green microalga with the great potential to generate natural ß-carotene. However, the corresponding mathematical models to guide optimized production of ß-carotene in Dunaliella salina (D. salina) are not yet available. In this study, dynamic models were proposed to simulate effects of environmental factors on cell growth and ß-carotene production in D. salina using online monitoring system. Moreover, the identification model of the parameter variables was established, and an adaptive particle swarm optimization algorithm based on parameter sensitivity analysis was constructed to solve the premature problem of particle swarm algorithm. The proposed kinetic model is characterized by high accuracy and predictability through experimental verification, which indicates its competence for future process design, control, and optimization. Based on the model established in this study, the optimal environmental factors for both ß-carotene production and microalgae growth were identified. The approaches created are potentially useful for microalga Dunaliella salina cultivation and high-value ß-carotene production.

Carbonate assisted lipid extraction and biodiesel production from wet microalgal biomass and recycling waste carbonate for CO2 supply in microalgae cultivation.

High cost of microalgal biofuel is caused by all the steps in current technology, including cultivation, harvesting, lipid extraction, biofuel processing and wastewater and waste treatment. This study aims to systematically reduce these costs with one integrated process, in which carbonate is used for cell rupture, lipid extraction and biodiesel processing, and then recycled for CO2 absorption and carbon supply for a new round of algae cultivation. To reach this goal, carbonate-heating treatment with N, N' - dibutylurea which can enhance cell disruption were used for cell-wall breaking of wet Neochloris oleoabundans (UTEX 1185) biomass. Lipid extraction was fulfilled with carbonate/ethanol aqueous two phase extraction method and residual carbonate with wastewater from bottom phase was recycled to absorb CO2 to generate bicarbonate for algal cultivation with fresh medium. Taking into comprehensive consideration of cell disruption efficiency, partition coefficient, and lipid recovery, the condition of cell disruption and lipid extraction was set at 90 °C, 100 min reaction time, 1:7.5 DBU:H2O (w/w) ratio, 1:3 Na2CO3:H2O (w/w) ratio, and 9% (w/wT) ethanol concentration. The results showed that carbonate-heating treatment of wet N. oleoabundans biomass resulted in up to 90.7% cell disruption efficiency. The lipid recovery rate in carbonate/ethanol system was up to 97.9%, and the final biodiesel production was 1.30 times of that with Soxhlet method. Utilization of the waste broth after CO2 absorption with the content of 4% (v/vT) in the medium for new batch of algae cultivation resulted in biomass concentration of 1.68 g/L. The corresponding total fatty acids production was 0.35 g/L, which was 1.63 fold of that with fresh medium. This study firstly proved the feasibility of using carbonate for lipid extraction and biodiesel production and recycle waste carbonate for carbon re-supply during algae cultivation.

Neobacillus sedimentimangrovi sp. nov., a Thermophilic Bacterium Isolated from Mangrove Sediment.

Two Gram-stain positive, rod-shaped, endospore-forming, aerobic, thermophilic strains, designated FJAT-2464T and FJAT-52740, were isolated from the sediment collected from Zhangjiang Estuary Mangrove National Nature Reserve in Fujian Province, China. The 16S rRNA gene sequence similarity between strains FJAT-2464T and FJAT-52740 was 100%. The result suggests that strains FJAT-2464T and FJAT-52740 belong to the same genome species, hence only FJAT-2464T was considered for further analysis. Strain FJAT-2464T showed the highest 16S rRNA gene sequence similarities to the type strains of Neobacillus thermocopriae SgZ-7T (99.9%), Neobacillus cucumis AP-6T (97.6%) and Neobacillus drentensis LMG 21831T (97.5%). Growth was observed at 25-65 °C (optimum 60 °C), pH 7.0-8.0 (optimum 8.0) with NaCl tolerance up to 1.0% (w/v) (optimum without NaCl %). The cell-wall peptidoglycan contained meso-diaminopimelic acid and MK-7 was the only respiratory quinone. The major fatty acids were iso-C15:0 and anteiso-C15:0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified aminophospholipid and unidentified lipids. The average nucleotide identity and digital DNA-DNA hybridization values between strain FJAT-2464T and the most closely related strain N. thermocopriae SgZ-7T was below the threshold value for species delineation. Based on the above results, strain FJAT-2464T represents a novel species of the genus Neobacillus, for which the name Neobacillus sedimentimangrovi sp. nov. is proposed. The type strain is FJAT-2464T (= MCCC 1K04406T = KCTC 43264T).