A Gram-positive, non-motile, white-pigmented, short rod actinobacterium, designated YIM 90734 T , was isolated from a saline soil sample collected from Ganjiahu Suosuo Forest National Nature Reserve in Xinjiang province, north-west China, and its taxonomic position was investigated by using a polyphasic approach. Strain YIM 90734 T grew optimally at 28-37 6C and pH 6.0-8.0 and in 5 % (w/v) NaCl. The peptidoglycan type was A4a, L-Lys-L-Ala-L-Glu and tyvelose and mannose were the major cell-wall sugars. The predominant menaquinones were MK-10 and MK-9. Major cellular fatty acids (.10 % of total) were anteiso-C 15 : 0 and anteiso-C 17 : 0 . The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown phospholipid and two unknown glycolipids. The DNA G+C content was 70.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 90734 T belonged to the genus Zhihengliuella. The 16S rRNA gene sequence similarity between strain YIM 90734 T and the type strain of the only recognized Zhihengliuella species, Zhihengliuella halotolerans, was 97.7 %. However, the level of DNA-DNA relatedness of the two strains was 41.4 %. The DNA-DNA relatedness data and differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain YIM 90734 T could be differentiated from Z.halotolerans. On the basis of the data presented, strain YIM 90734 T is considered to represent a novel species of the genus Zhihengliuella, for which the name Zhihengliuella alba sp. nov. is proposed. The type strain is YIM 90734 T (5KCTC 19375 T 5DSM 21143 T ). The description of the genus Zhihengliuella has also been emended. et al. (2007) and initially contained only one species, Zhihengliuella halotolerans (type strain YIM 70185 T ), which was isolated from Qinghai province, north-west China. The genus Zhihengliuella is described as comprising a Grampositive, non-motile, short-rod actinobacterium that was catalase-positive and oxidase-negative. The peptidoglycan type was A4a, L-Lys-L-Ala-L-Glu. Cell-wall sugars contained tyvelose and glucose. The predominant menaquinones were MK-9 and MK-10 and the major fatty acids were anteiso-C 15 : 0 and iso-C 15 : 0 . The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol. The G+C content of the genomic DNA was about 66.5 mol% . In this paper, we describe the characterization and classification of a halotolerant actinobacterium, designated YIM 90734 T , which was isolated from a saline sample collected from Ganjiahu Suosuo Forest National Nature Reserve in Xinjiang province, north-west China and was considered to represent a novel species of the genus Zhihengliuella. The genus Zhihengliuella was first established by Zhang Strain YIM 90734T was isolated from a saline soil sample after 3 weeks incubation at 37 u C on modified ISP 5 medium comprising (1 21 distilled water, final pH 7.5): 1 g L-asparagine, 10 g glycerol, 5 g yeast extract, 1 g K 2 HPO 4 , 5 g KNO 3 , 100 g NaC...

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This experiment was conducted to evaluate the effects of dietary inclusion of Bacillus licheniformis on laying performance, egg quality, antioxidant enzyme activities, and intestinal barrier function of laying hens. Hy-Line Variety W-36 hens (n = 540; 28 wk of age) were randomized into 6 groups, each group with 6 replications (n = 15). The control group received the basal diet formulated with maize and soybean meal. The treatment groups received the same basal diets supplemented with 0.01, 0.02, 0.03, 0.06, and 0.09% Bacillus licheniformis powder (2 × 10(10) cfu/g) for an 8-wk trial. The results showed that dietary supplementation with 0.01 and 0.03% B. licheniformis significantly increased egg production and egg mass. However, no significant differences were observed in egg weight, feed consumption, and feed conversion efficiency among the 6 groups. Supplementation with different levels of B. licheniformis was found to be effective in improvement of egg quality by increasing egg shell thickness and strength. Compared with control, d-lactate content, diamine oxidase activity, and adrenocorticotropic hormone level in serum decreased significantly, and the level of estradiol and follicle-stimulating hormone increased significantly in plasma of all the experimental groups. Dietary supplementation with B. licheniformis increased the intestinal villus height and reduced the crypt depth. In conclusion, dietary inclusion of B. licheniformis could improve laying performance and egg quality significantly in a dose-dependent manner by decreasing the stress response, upregulating the growth hormone, and improving intestinal health.

Plants harbors complex and variable microbial communities. Endophytic bacteria play an important function and potential role more effectively in developing sustainable systems of crop production. To examine how endophytic bacteria in sugar beet (Beta vulgaris L.) vary across both host growth period and location, PCR-based Illumina was applied to revealed the diversity and stability of endophytic bacteria in sugar beet on the north slope of Tianshan mountain, China. A total of 60.84 M effective sequences of 16S rRNA gene V3 region were obtained from sugar beet samples. These sequences revealed huge amount of operational taxonomic units (OTUs) in sugar beet, that is, 19-121 OTUs in a beet sample, at 3 % cutoff level and sequencing depth of 30,000 sequences. We identified 13 classes from the resulting 449,585 sequences. Alphaproteobacteria were the dominant class in all sugar beets, followed by Acidobacteria, Gemmatimonadetes and Actinobacteria. A marked difference in the diversity of endophytic bacteria in sugar beet for different growth periods was evident. The greatest number of OTUs was detected during rossette formation (109 OTUs) and tuber growth (146 OTUs). Endophytic bacteria diversity was reduced during seedling growth (66 OTUs) and sucrose accumulation (95 OTUs). Forty-three OTUs were common to all four periods. There were more tags of Alphaproteobacteria and Gammaproteobacteria in Shihezi than in Changji. The dynamics of endophytic bacteria communities were influenced by plant genotype and plant growth stage. To the best of our knowledge, this study is the first application of PCR-based Illumina pyrosequencing to characterize and compare multiple sugar beet samples.

BackgroundAs bacteria-originated crude violacein, a natural indolocarbazole product, consists of violacein and deoxyviolacein, and can potentially be a new type of natural antibiotics, the reconstruction of an effective metabolic pathway for crude violacein (violacein and deoxyviolacein mixture) synthesis directly from glucose in Escherichia coli was of importance for developing industrial production process.ResultsStrains with a multivariate module for varied tryptophan productivities were firstly generated by combinatorial knockout of trpR/tnaA/pheA genes and overexpression of two key genes trpEfbr/trpD from the upstream tryptophan metabolic pathway. Then, the gene cluster of violacein biosynthetic pathway was introduced downstream of the generated tryptophan pathway. After combination of these two pathways, maximum crude violacein production directly from glucose by E. coli B2/pED + pVio was realized with a titer of 0.6 ± 0.01 g L−1 in flask culture, which was four fold higher than that of the control without the tryptophan pathway up-regulation. In a 5-L bioreactor batch fermentation with glucose as the carbon source, the recombinant E. coli B2/pED + pVio exhibited a crude violacein titer of 1.75 g L−1 and a productivity of 36 mg L−1 h−1, which was the highest titer and productivity reported so far under the similar culture conditions without tryptophan addition.ConclusionMetabolic pathway analysis using 13C labeling illustrated that the up-regulated tryptophan supply enhanced tryptophan metabolism from glucose, whereas the introduction of violacein pathway drew more carbon flux from glucose to tryptophan, thereby contributing to the effective production of crude violacein in the engineered E. coli cell factory.Electronic supplementary materialThe online version of this article (doi:10.1186/s12934-015-0192-x) contains supplementary material, which is available to authorized users.

The construction of a minimal cell that exhibits the essential characteristics of life is a great challenge in the field of synthetic biology. Assembling a minimal cell requires multidisciplinary expertise from physics, chemistry and biology. Scientists from different backgrounds tend to define the essence of 'life' differently and have thus proposed different artificial cell models possessing one or several essential features of living cells. Using the tools and methods of molecular biology, the bottom-up engineering of a minimal cell appears in reach. However, several challenges still remain. In particular, the integration of individual sub-systems that is required to achieve a self-reproducing cell model presents a complex optimization challenge. For example, multiple self-organisation and self-assembly processes have to be carefully tuned. We review advances and developments of new methods and techniques, for cell-free protein synthesis as well as micro-fabrication, for their potential to resolve challenges and to accelerate the development of minimal cells.

Very little is known about the physiological interactions between plants and endophytic bacteria. We investigated the impact of three endophytic bacteria, Bacillus pumilus 2-1, Chryseobacterium indologene 2-2, and Acinetobacter johnsonii 3-1, on the photosynthetic capacity and growth of sugar beet. Endophyte-free plants were obtained first and infected with the bacteria. Measurements of total chlorophyll content revealed very significant differences between endophyte-free beet plants and some infected by endophytic bacteria. The maximum photochemical yield (Fv/Fm) was used to determine any photosynthetic effect on plants caused by biotic or abiotic factors. After 30 days of growth, there was significantly higher Fv/Fm for endophyte-infected than endophyte-free plants. The light response curves of beet showed that photosynthetic capacity was significantly increased in endophyte-infected plants. Photosynthesis of endophyte-free plants was saturated at 1,300 micromol m(-2) s(-1), whereas endophyte-infected plants were not saturated at the irradiance used. The effect seemed to be due to promotion of electron transport in the thylakoid membranes. Promotion of photosynthetic capacity in sugar beet was due to increased chlorophyll content, leading to a consequent increased carbohydrate synthesis. It is possible that the increased maximum yield of photosynthesis in sugar beet was promoted by phytohormones and produced by the bacteria.