Sinomicrobium weinanense sp. nov., a halophilic bacterium isolated from saline-alkali soil.

A Gram-stain-negative, facultative anaerobic, non-motile, rod-shaped strain was isolated from saline-alkali soil collected in PR China, and it was designated as strain FJxsT. Its optimal growth was observed at 37-40 °C in the presence of 0-3 % (w/v) NaCl (pH 7.0). The major fatty acids of strain FJxsT were iso-C15 : 0, iso-C17 : 0 3OH, summed feature 3, C16 : 0 and iso-C15 : 1 G. The predominant respiratory quinone was menaquinone 6. The DNA G+C content of the strain was 45.18 mol%. Whole genome and 16S rRNA gene sequence analyses indicated that strain FJxsT exhibited 94.78 % sequence identity (the maximum) with Sinomicrobium soli N-1-3-6T, 94.36 % with Sinomicrobium pectinilyticum 5DNS001T, and 93.52 % with Sinomicrobium oceani SCSIO 03483T. Analyses of genotypic, phenotypic, phylogenetic and chemotaxonomic characteristics indicated that strain FJxsT represented a novel species of the genus Sinomicrobium. This novel species was named Sinomicrobium weinanense sp. nov. with its type strain as FJxsT (=CCTCC AB 2019251T=KCTC 72740T).

Ultra-compact dual-mode mode-size converter for silicon photonic few-mode fiber interfaces.

Fiber couplers usually take a lot of space on photonic integrated circuits due to the large mode-size mismatch between the waveguide and fiber, especially when a fiber with larger core is utilized, such as a few-mode fiber. We demonstrate experimentally that such challenge can be overcome by an ultra-compact mode-size converter with a footprint of only 10 µm. Our device expands TE0 and TE1 waveguide modes simultaneously from a 1-µm wide strip waveguide to an 18-µm wide slab on a 220-nm thick silicon-on-insulator, with calculated losses of 0.75 dB and 0.68 dB, respectively. The fabricated device has a measured insertion loss of 1.02 dB for TE0 mode and 1.59 dB for TE1 mode. By connecting the ultra-compact converter with diffraction grating couplers, higher-order modes in a few-mode fiber can be generated with a compact footprint on-chip.

Ultrasensitive temperature sensor with Vernier-effect improved fiber Michelson interferometer.

A novel fiber Michelson interferometer (FMI) based on parallel dual polarization maintaining fiber Sagnac interferometers (PMF-SIs) is proposed and experimentally demonstrated for temperature sensing. The free spectral range (FSR) difference of dual PMF-SIs determines the FSR of envelope and sensitivity of the sensor. The temperature sensitivity of parallel dual PMF-SIs is greatly enhanced by the Vernier effect. Experimental results show that the temperature sensitivity of the proposed sensor is improved from -1.646 nm/°C (single PMF-SI) to 78.984 nm/°C (parallel dual PMF-SIs), with a magnification factor of 47.99, and the temperature resolution is improved from ±0.03037°C to ±0.00063°C by optimizing the FSR difference between the two PMF-SIs. Our proposed ultrasensitive temperature sensor is with easy fabrication, low cost and simple configuration which can be implemented for various real applications that need high precision temperature measurement.

Liquid-cladded optical phased array for a single-wavelength beam steering.

We report a simple concept to implement a single-wavelength beam steering based on a liquid-cladded one-dimensional (1D) optical phased array (OPA). The beam steering was realized by modifying the waveguide mode effective index through replacing the liquid upper claddings. A prototype of a 32-channel liquid-cladded OPA was fabricated and characterized. Owing to the high refractive index range of liquids (>0.625), a maximum steering angle of >10∘ was achieved with the liquid range from 1.0 to 1.63 at a wavelength of 940 nm. Moreover, the liquid-cladded OPA reveals a quasi-continuous beam steering range of >29∘ by combining the liquid cladding tuning and discrete wavelength tuning of λ=785nm, 852 nm, and 940 nm. Further integration with optofluidic systems offers the OPA potential for low power consumption and all-fluidic beam steering operating at a single wavelength.

Broadband silicon nitride nanophotonic phased arrays for wide-angle beam steering.

In this Letter, the broadband operation in wavelengths from 520 nm to 980 nm is demonstrated on silicon nitride nanophotonic phased arrays. The widest beam steering angle of 65° on a silicon nitride phased array is achieved. The optical radiation efficiency of the main grating lobe in a broad wavelength range is measured and analyzed theoretically. The optical spots radiated from the phased array chip are studied at different wavelengths of lasers. The nanophotonic phased array is excited by a supercontinuum laser source for a wide range of beam steering for the first time to the best of our knowledge. It paves the way to tune the wavelength from visible to near infrared range for silicon nitride nanophotonic phased arrays.

Parallel emitted silicon nitride nanophotonic phased arrays for two-dimensional beam steering.

In this Letter, a two-dimensional (2D) beam steering on silicon nitride (SiNx) nanophotonic phased arrays from visible to near-infrared wavelengths is reported for the first time, to the best of our knowledge. In order to implement beam steering along the transverse direction for one-dimensional waveguide surface grating arrays, wavelengths from 650 to 980 nm provided by the supercontinuum laser are used to excite the phased array. Then the beams are parallel radiated with steering angles in a sequence of 26.84° to -16.54∘ along the transverse direction, and a continuous line in the far field consisting of parallel emitted spots is produced with a total view angle of 43.38°. Moreover, this continuous far-field line is steered along the longitudinal direction with massive wavelengths simultaneously tuned by phase shifts from -π/2 to over +π/2. This method with massive parallel wavelengths emitted paves a new way for 2D steering on SiNx nanophotonic phased arrays.

A compact and polarization-insensitive silicon waveguide crossing based on subwavelength grating MMI couplers.

In this work, we proposed and experimentally demonstrated a compact and low polarization-dependent silicon waveguide crossing based on subwavelength grating multimode interference couplers. The subwavelength grating structure decreases the effective refractive index difference and shrinks the device footprint. Our designed device is fabricated on the 220-nm SOI platform and performs well. The measured crossing is characterized with low insertion loss (< 1 dB), low polarization-dependence loss (< 0.6 dB), and low crosstalk (< -35 dB) for both TE and TM polarizations with a compact footprint of 12.5 µm × 12.5 µm.

Packaged microbubble resonator optofluidic flow rate sensor based on Bernoulli Effect.

A novel flow sensor based on dynamic fluid pressure changing in a packaged microbubble resonator without additional modification on its structure has been proposed and experimentally demonstrated. The results of sensing performance under both tunable laser source and broadband light source are presented. The flow rate sensitivity can reach up to 0.0196 pm / (µL/min). The fluid pressure variation caused by Bernoulli Effect is also analyzed theoretically.

Optical Spring Effect in Micro-Bubble Resonators and Its Application for the Effective Mass Measurement of Optomechanical Resonant Mode.

In this work, we present a novel approach for obtaining the effective mass of mechanical vibration mode in micro-bubble resonators (MBRs). To be specific, the effective mass is deduced from the measurement of optical spring effect (OSE) in MBRs. This approach is demonstrated and applied to analyze the effective mass of hollow MBRs and liquid-filled MBRs, respectively. It is found that the liquid-filled MBRs has significantly stronger OSE and a less effective mass than hollow MBRs, both of the extraordinary behaviors can be beneficial for applications such as mass sensing. Larger OSE from higher order harmonics of the mechanical modes is also observed. Our work paves a way towards the developing of OSE-based high sensitive mass sensor in MBRs.

2-D optical/opto-mechanical microfluidic sensing with micro-bubble resonators.

In this paper a new sensing scheme by simultaneously measuring optical refractive index change and sound speed change in an optofluidic thin wall micro-bubble resonator is reported. Sensitivity of sound speed is 4.2-6.8 MHz/ (km/s) for 3 types of mechanical modes. A 2-D optical/opto-mechanical sensing map is plotted by detecting both the whispering gallery mode resonance shift and the optomechanical resonance shift. This novel scheme provides a supplementary support to optical sensing when analytes do not respond to refractive index (RI) change.

Deleting multiple lytic genes enhances biomass yield and production of recombinant proteins by Bacillus subtilis.

BACKGROUND: Bacillus subtilis is widely used in agriculture and industrial biotechnology; however, cell autolysis significantly decreases its yield in liquid cultures. Numerous factors mediate the lysis of B. subtilis, such as cannibalism factors, prophages, and peptidoglycan (PG) hydrolases. The aim of this work was to use molecular genetic techniques to develop a new strategy to prevent cell lysis and enhance biomass as well as the production of recombinant proteins. RESULTS: Five genes or genetic elements representing three different functional categories were studied as follows: lytC encoding PG hydrolases, the prophage genes xpf and yqxG-yqxH-cwlA (yGlA), and skfA and sdpC that encode cannibalism factors. Cell lysis was reduced and biomass was enhanced by deleting individually skfA, sdpC, xpf, and lytC. We constructed the multiple deletion mutant LM2531 (skfA sdpC lytC xpf) and found that after 4 h of culture, its biomass yield was significantly increased compared with that of prototypical B. subtilis 168 (wild-type) strain and that 15% and 92% of the cells were lysed in cultures of LM2531 and wild-type, respectively. Moreover, two expression vectors were constructed for producing recombinant proteins (ß-galactosidase and nattokinase) under the control of the P43 promoter. Cultures of LM2531 and wild-type transformants produced 13741 U/ml and 7991 U/ml of intracellular ß-galactosidase, respectively (1.72-fold increase). Further, the level of secreted nattokinase produced by strain LM2531 increased by 2.6-fold compared with wild-type (5226 IU/ml vs. 2028 IU/ml, respectively). CONCLUSIONS: Our novel, systematic multigene deletion approach designed to inhibit cell lysis significantly increased the biomass yield and the production of recombinant proteins by B. subtilis. These findings show promise for guiding efforts to manipulate the genomes of other B. subtilis strains that are used for industrial purposes.

An all-optical multidirectional mechano-sensor inspired by biologically mechano-sensitive hair sensilla.

Mechano-sensitive hair-like sensilla (MSHS) have an ingenious and compact three-dimensional structure and have evolved widely in living organisms to perceive multidirectional mechanical signals. Nearly all MSHS are iontronic or electronic, including their biomimetic counterparts. Here, an all-optical mechano-sensor mimicking MSHS is prototyped and integrated based on a thin-walled glass microbubble as a flexible whispering-gallery-mode resonator. The minimalist integrated device has a good directionality of 32.31 dB in the radial plane of the micro-hair and can detect multidirectional displacements and forces as small as 70 nm and 0.9 µN, respectively. The device can also detect displacements and forces in the axial direction of the micro-hair as small as 2.29 nm and 3.65 µN, respectively, and perceive different vibrations. This mechano-sensor works well as a real-time, directional mechano-sensory whisker in a quadruped cat-type robot, showing its potential for innovative mechano-transduction, artificial perception, and robotics applications.

Clinicopathological characteristics and associated factors of idiopathic membranous nephropathy with hyperuricemia: a single-centered cross-sectional study.

PURPOSE: This study was designed to investigate the clinicopathological features of idiopathic membranous nephropathy (IMN) with hyperuricemia (HUA), together with associated factors within 10 years in a single centre in Shandong Province. METHODS: In this cross-sectional study, we analysed the clinical and pathological data of 694 IMN patients in our hospital from January 2010 to December 2019. Based on serum uric acid (UA) level, the patients were divided into hyperuricemia (HUA) group (n = 213) and normal serum uric acid (NUA) group (n = 481). Multi-variate logistic regression analysis was conducted on to screen the associated factors of HUA. RESULTS: 213 (30.69%) IMN patient were complicated with HUA. Compared with the patients with NUA, significant increase was noticed in the proportion of patients showing edema, concurrent hypertensive disease or diabetes mellitus (DM), as well as the proportion of positive glomerular capillary loop IgM and positive C1q in the HUA group (P < 0.05). In addition, significant increase was noticed in the 24 h urine protein, serum creatinine, triglycerides, complement C3 and complement C4 in HUA group compared with those of NUA group (all P < 0.05). With gender as a control factor, multi-variate logistic regression analysis showed positive glomerular capillary loops C1q, serum albumin, serum phosphorus were associated with IMN combined with HUA in male, while triglycerides and serum creatinine were associated with IMN combined with HUA in female counterparts. CONCLUSION: About 30.69% of IMN patients had HUA, with a male predominance than female. In male patients with IMN, higher serum albumin level and serum phosphorus level were associated with higher incidence of HUA, while in female IMN patients, higher serum triglyceridemia and serum creatinine level were associated with higher incidence of HUA. Therefore, it can be targeted to prevent the occurrence of HUA in IMN.

Improving NH3 and H2S removal efficiency with pilot-scale biotrickling filter by co-immobilizing Kosakonia oryzae FB2-3 and Acinetobacter baumannii L5-4.

In this study, two NH4+-N and S2- removal strains, namely, Kosakonia oryzae (FB2-3) and Acinetobacter baumannii (L5-4), were isolated from the packing materials in a long-running biotrickling filter (BTF). The removal capacities of combined FB2-3 and L5-4 (FB2-3 + L5-4) toward 100 mg L-1 of NH4+-N and 200 mg L-1 of S2- reached 97.31 ± 1.62% and 98.57 ± 1.12% under the optimal conditions (32.0 °C and initial pH = 7.0), which were higher than those of single strain. Then, FB2-3 and L5-4 liquid inoculums were prepared, and their concentrations respectively reached 1.56 × 109 CFU mL-1 and 1.05 × 109 CFU mL-1 by adding different resuspension solutions and protective agents after 12-week storage at 25 °C. Finally, pilot-scale BTF test showed that NH3 and H2S in the real exhaust gases from a pharmaceutical factory were effectively removed with removal rates > 87% and maximum elimination capacities were reached 136 g (NH3) m-3 h-1 and 176 g (H2S) m-3 h-1 at 18 °C-34 °C and pH 4.0-7.0 in the BTF loaded with bamboo charcoal packing materials co-immobilized with FB2-3 and L5-4. After co-immobilization of FB2-3 and L5-4, in the bamboo charcoal packing materials, the new microbial diversity composition contained the dominant genera of Acinetobacter, Mycobacterium, Kosakonia, and Sulfobacillus was formed, and the diversity of entire bacterial community was decreased, compared to the control. These results indicate that FB2-3 and L5-4 have potential to be developed into liquid ready-to-use inoculums for effectively removing NH3 and H2S from exhaust gases in BTF.

[Synthesis of the Zn2SiO4 : Eu3+ red phosphor by sol-gel method].

Spherical Zn2 SiO4 : Eu3+ phosphors were prepared by a Pechini sol-gel process. The microstructure and luminescent properties of the obtained Zn2 SiO4 : Eu3+ particles were well characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and photoluminescence (PL) spectra. The results of SEM demonstrated that the Zn2 SiO4 : Eu3+ particles with a diameter about 1 -3microm, which have spherical morphology, emitted an intensive red light emission at 613 nm under excitation at 395 nm. Besides, the effects of the Eu3+ concentration, annealing temperature and charge compensators of Li+ ions on the PL emission intensities were investigated in detail. The investigation showed that the PL intensity increased with the annealing temperature increasing. At the same time, the PL intensity firstly increased and then decreased with the Eu3+ and Li+ concentration increasing.

Stress preadaptation and overexpression of rpoS and hfq genes increase stress resistance of Pseudomonas fluorescens ATCC13525.

Pseudomonas fluorescens ATCC13525 is an important growth-promoting rhizobacteria (PGPR) and plant disease biocontrol bacterium. However, due to poor stress resistance, it is prone to be inactivated by preparation, drying and storage. In this study, we investigated the effects of different stress preadaptation methods (2.0∼3.0 wt% NaCl, 0.01∼0.20 wt% H2O2, and 35∼44 °C) and two stress adaptation genes (rpoS, and hfq) on the stress resistance of P. fluorescens ATCC13525 (PF-WT). After stress preadaptation with low stress of 3.0 wt% NaCl, 0.05 wt% H2O2, and 41 °C for 30 min, the tolerance of PF-WT toward high lethal stress environments (20.0 wt% NaCl, 1.00 wt% H2O2, and 47 °C) were significantly improved. Moreover, knockout of rpoS and hfq genes resulted in slower culture growth than PF-WT under the sublethal stress culture conditions (5.0 wt% NaCl, 0.08 wt% H2O2, and 35 °C), whereas rpoS and hfq overexpressed strains (PF-pBBR2-rpoS and PF-pBBR2-hfq) obviously grew better than the control strain PF-pBBR2. Further, we prepared biocontrol agents (BACs) of different strains after different stress preadaptation treatments. Compared to PF-WT without stress preadaptation, preadaptation by 0.05 wt% H2O2 for 30 min resulted in 5.65 times higher survival rate, while treatment with 3.0 wt% NaCl for 30 min of PF-pBBR2-rpoS led to 5.60 times higher survival rate. This finding provides the simple and effective protection methods for P. fluorescens ATCC13525 BACs preparation by stress preadaptation and overexpression of stress adaptation genes.

Differences in Acid Stress Response of Lacticaseibacillus paracasei Zhang Cultured from Solid-State Fermentation and Liquid-State Fermentation.

Liquid-state fermentation (LSF) and solid-state fermentation (SSF) are two forms of industrial production of lactic acid bacteria (LAB). The choice of two fermentations for LAB production has drawn wide concern. In this study, the tolerance of bacteria produced by the two fermentation methods to acid stress was compared, and the reasons for the tolerance differences were analyzed at the physiological and transcriptional levels. The survival rate of the bacterial agent obtained from solid-state fermentation was significantly higher than that of bacteria obtained from liquid-state fermentation after spray drying and cold air drying. However, the tolerance of bacterial cells obtained from liquid-state fermentation to acid stress was significantly higher than that from solid-state fermentation. The analysis at physiological level indicated that under acid stress, cells from liquid-state fermentation displayed a more solid and complete membrane structure, higher cell membrane saturated fatty acid, more stable intracellular pH, and more stable activity of ATPase and glutathione reductase, compared with cells from solid-state fermentation, and these physiological differences led to better tolerance to acid stress. In addition, transcriptomic analysis showed that in the cells cultured from liquid-state fermentation, the genes related to glycolysis, inositol phosphate metabolism, and carbohydrate transport were down-regulated, whereas the genes related to fatty acid synthesis and glutamate metabolism were upregulated, compared with those in cells from solid-state fermentation. In addition, some genes related to acid stress response such as cspA, rimP, rbfA, mazF, and nagB were up-regulated. These findings provide a new perspective for the study of acid stress tolerance of L. paracasei Zhang and offer a reference for the selection of fermentation methods of LAB production.

Greater enhancement of Bacillus subtilis spore yields in submerged cultures by optimization of medium composition through statistical experimental designs.

Bacillus subtilis spore preparations are promising probiotics and biocontrol agents, which can be used in plants, animals, and humans. The aim of this work was to optimize the nutritional conditions using a statistical approach for the production of B. subtilis (WHK-Z12) spores. Our preliminary experiments show that corn starch, corn flour, and wheat bran were the best carbon sources. Using Plackett-Burman design, corn steep liquor, soybean flour, and yeast extract were found to be the best nitrogen source ingredients for enhancing spore production and were studied for further optimization using central composite design. The key medium components in our optimization medium were 16.18 g/l of corn steep liquor, 17.53 g/l of soybean flour, and 8.14 g/l of yeast extract. The improved medium produced spores as high as 1.52 +/- 0.06 x 10(10) spores/ml under flask cultivation conditions, and 1.56 +/- 0.07 x 10(10) spores/ml could be achieved in a 30-l fermenter after 40 h of cultivation. To the best of our knowledge, these results compared favorably to the documented spore yields produced by B. subtilis strains.

State-of-the-Art Optical Microfiber Coupler Sensors for Physical and Biochemical Sensing Applications.

An optical fiber coupler is a simple and fundamental component for fiber optic technologies that works by reducing the fiber diameter to hundred nanometers or several micrometers. The microfiber coupler (MFC) has regained interest in optical fiber sensing in recent years. The subwavelength diameter rationales vast refractive index (RI) contrast between microfiber "core" and surrounding "cladding", a large portion of energy transmits in the form of an evanescent wave over the fiber surface that determines the MFC ultrasensitive to local environmental changes. Consequently, MFC has the potential to develop as a sensor. With the merits of easy fabrication, low cost and compact size, numerous researches have been carried out on different microfiber coupler configurations for various sensing applications, such as refractive index (RI), temperature, humidity, magnetic field, gas, biomolecule, and so on. In this manuscript, the fabrication and operation principle of an MFC are elaborated and recent advances of MFC-based sensors for scientific and technological applications are comprehensively reviewed.

Differential Analysis of Stress Tolerance and Transcriptome of Probiotic Lacticaseibacillus casei Zhang Produced from Solid-State (SSF-SW) and Liquid-State (LSF-MRS) Fermentations.

The property differences between bacteria produced from solid-state and liquid-state fermentations have always been the focus of attention. This study analyzed the stress tolerance and transcriptomic differences of the probiotic Lacticaseibacillus casei Zhang produced from solid-state and liquid-state fermentations under no direct stress. The total biomass of L. casei Zhang generated from liquid-state fermentation with MRS medium (LSF-MRS) was 2.24 times as much as that from solid-state fermentation with soybean meal-wheat bran (SSF-SW) medium. Interestingly, NaCl, H2O2, and ethanol stress tolerances and the survival rate after L. casei Zhang agent preparation from SSF-SW fermentation were significantly higher than those from LSF-MRS fermentation. The global transcriptomic analysis revealed that in L. casei Zhang produced from SSF-SW fermentation, carbohydrate transport, gluconeogenesis, inositol phosphate metabolism were promoted, that pentose phosphate pathway was up-regulated to produce more NADPH, that citrate transport and fermentation was extremely significantly promoted to produce pyruvate and ATP, and that pyruvate metabolism was widely up-regulated to form lactate, acetate, ethanol, and succinate from pyruvate and acetyl-CoA, whereas glycolysis was suppressed, and fatty acid biosynthesis was suppressed. Moreover, in response to adverse stresses, some genes encoding aquaporins (GlpF), superoxide dismutase (SOD), nitroreductase, iron homeostasis-related proteins, trehalose operon repressor TreR, alcohol dehydrogenase (ADH), and TetR/AcrR family transcriptional regulators were up-regulated in L. casei Zhang produced from SSF-SW fermentation. Our findings provide novel insight into the differences in growth performance, carbon and lipid metabolisms, and stress tolerance between L. casei Zhang from solid-state and liquid-state fermentations.