To avoid costly biomass recovery in photosynthetic microbial biofuel production, we genetically modified cyanobacteria to produce and secrete fatty acids. Starting with introducing an acyl-acyl carrier protein thioesterase gene, we made six successive generations of genetic modifications of cyanobacterium Synechocystis sp. PCC6803 wild type (SD100). The fatty acid secretion yield was increased to 197 AE 14 mg∕L of culture in one improved strain at a cell density of 1.0 × 10 9 cells∕mL by adding codon-optimized thioesterase genes and weakening polar cell wall layers. Although these strains exhibited damaged cell membranes at low cell densities, they grew more rapidly at high cell densities in late exponential and stationary phase and exhibited less cell damage than cells in wild-type cultures. Our results suggest that fatty acid secreting cyanobacteria are a promising technology for renewable biofuel production.

The most prevalent pathological features of many neurodegenerative diseases are the aggregation of misfolded proteins and the loss of certain neuronal populations. Autophagy, as major intracellular machinery for degrading aggregated proteins and damaged organelles, has been reported to be involved in the occurrence of pathological changes in many neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis. In this review, we summarize most recent research progress in this topic and provide a new perspective regarding autophagy regulation on the pathogenesis of neurodegenerative diseases. Finally, we discuss the signaling molecules in autophagy-related pathways as therapeutic targets for the treatment of these diseases.

Aims The aim of this study was to estimate the burden and risk factors for ischaemic heart disease (IHD) in 195 countries and territories from 1990 to 2017. Methods and results Data from the Global Burden of Disease Study 2017 were used. Prevalence, incidence, deaths, years lived with disability (YLDs), and years of life lost (YLLs) were metrics used to measure IHD burden. Population attributable fraction was used to estimate the proportion of IHD deaths attributable to potentially modifiable risk factors. Globally, in 2017, 126.5 million [95% uncertainty interval (UI) 118.6 to 134.7] people lived with IHD and 10.6 million (95% UI 9.6 to 11.8) new IHD cases occurred, resulting in 8.9 million (95% UI 8.8 to 9.1) deaths, 5.3 million (95% UI 3.7 to 7.2) YLDs, and 165.0 million (95% UI 162.2 to 168.6) YLLs. Between 1990 and 2017, despite the decrease in age-standardized rates, the global numbers of these burden metrics of IHD have significantly increased. The burden of IHD in 2017 and its temporal trends from 1990 to 2017 varied widely by geographic location. Among all potentially modifiable risk factors, age-standardized IHD deaths worldwide were primarily attributable to dietary risks, high systolic blood pressure, high LDL cholesterol, high fasting plasma glucose, tobacco use, and high body mass index in 2017. Conclusion Our results suggested that IHD remains a major public health challenge worldwide. More effective and targeted strategies aimed at implementing cost-effective interventions and addressing modifiable risk factors are urgently needed, particularly in geographies with high or increasing burden.

We designed and constructed a controllable inducing lysis system in Synechocystis sp. PCC 6803 to facilitate extracting lipids for biofuel production. Several bacteriophage-derived lysis genes were integrated into the genome and placed downstream of a nickel-inducible signal transduction system. We applied 3 strategies: (i) directly using the phage lysis cassette, (ii) constitutively expressing endolysin genes while restricting holin genes, and (iii) combining lysis genes from different phages. Significant autolysis was induced in the Synechocystis sp. PCC 6803 cells with this system by the addition of NiSO4. Our inducible cyanobacterial lysing system eliminates the need for mechanical or chemical cell breakage and could facilitate recovery of biofuel from cyanobacteria.biofuel ͉ phage lysis genes P hotosynthetic microorganisms, including eukaryotic algae and cyanobacteria, are being optimized to overproduce numerous products of value (1). Because of the global energy shortage and climate change caused by greenhouse gas emission, the scientific community has focused on developing renewable biofuels from photosynthetic microorganisms (2). Cyanobacteria are excellent organisms for biofuel production. Unlike algae, their genomes are relatively easy to manipulate. They are efficient at converting solar energy, and, unlike energy crops, they can be grown on non-arable land (3). We thus have selected Cyanobacterium Synechocystis sp. PCC 6803 (hereafter referred to as Synechocystis 6803) as a model organism to develop methods for easy recovery of lipids for use in biofuel production.The first goal of our research was to disrupt the cyanobacterial cell envelope to facilitate lipid recovery from biomass. Seog et al. (4) used various methods, such as sonication, French press, bead-beater, and lyophilization, to disrupt the cell envelops of the alga Botryococcus braunii. Extraction was 1.96 times more efficient using the bead-beater method than by using solvents alone, suggesting that a proper method of cell disruption could facilitate lipid extraction by damaging the cell wall. However, the bead-beater method is not economical for large amounts of biomass. There are some alternative cell-breakage methods, e.g., pulsed electric field (5) and hydrolytic enzymes (6), but all these methods add additional cost and reduce the overall utility of the process. Our strategy is simply to make the cyanobacteria lyse at the appropriate time.The cyanobacterial cell envelope is composed of 4 layers (7) (Fig. 1): the external surface layers (such as S-layers and carbohydrate structures), the outer membrane, the polypeptidoglycan layer (8), and the cytoplasmic membrane. Despite the overall gram-negative structure, the peptidoglycan layer found in cyanobacteria is considerably thicker than that of most gramnegative bacteria (8). In addition, the degree of crosslinking between the peptidoglycan chains within the cell wall layer of cyanobacteria (56-63%) is far higher than that in most gramnegative bacteria (20-33%) (9).To break up the pepti...