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A protease AP3 from Aspergillus hennebergii HX08 was purified by ammonium-sulphate precipitation, followed by anion-exchange chromatography and gel filtration. The molecular weight of acid protease AP3 was 33 kDa (SDS-PAGE and MALDI-TOF-MS). The protease AP3 was identified as an acid protease with MALDI-TOF/TOF tandem MS. Its optimal temperature and pH were 60°C and 4.0, respectively. Its Kmax and Vmax were 57.92 mg/mL and 32.57 U/mL, respectively. The enzyme was active over a broad pH and temperature range (pH 3.0-5.0 and 30-60°C), and exhibited high activity and stability in 2-12% ( v/v) ethanol solvent. Subsequent studies suggest that the enzyme presents a relatively high substrate affinity to wheat protein (98% of total activity). Its application to solid-state fermentation of wheat flour with Saccharomyces cerevisiae could increase the hydrolysis degree of wheat protein (28.26%) and amino acid nitrogen concentration of fermented grains (34.21%). Additionally, enhanced S. cerevisiae biomass (37.09%) and alcohol concentration (38.29%) were also observed during the process. Volatile compounds analysis of fermented grains by headspace solid-phase micro-extraction and GC-MS revealed more flavour compounds. These results suggest its potential in food and alcohol industries. Copyright © 2017 The Institute of Brewing & Distilling [ABSTRACT FROM AUTHOR]

Among Chinese traditional distilled liquors, Moutai-flavoured liquor is the most famous, owing to its complicated process as it is derived from fermented sorghum coupled with the use of a Moutai-flavoured Daqu. In this study, a novel isolate, belonging to a black Aspergillus, was obtained and identified as Aspergillus hennebergii by ITS-5.8S rRNA sequencing analysis and conventional morphologic identification. The influences of initial pH, carbon source, nitrogen source and metal ions on the production of an A. hennebergii protease were studied. The results revealed that metal ions exerted a significant effect on enzyme production and activity. Additionally, the potential application of the protease from A. hennebergii was investigated. The enzymatic hydrolysis resulted in the identification and quantification of 42 compounds, including alcohols, aldehydes, pyrazines and esters. These volatile compounds exhibited special flavour properties. Significant differences were observed between the enzyme treatments and the control sample. Samples from the enzyme treatments led to the highest amounts of alcohols, pyrazines and aromatics. These results suggest that A. hennebergii, or its protease, may have some application values for the enhancement of the quality of Chinese liquor and for the improvement of the liquor production process. Copyright © 2014 The Institute of Brewing & Distilling [ABSTRACT FROM AUTHOR]

A dual-wavelength DFB laser array based on four phase-shifted grating and equivalent chirp technology is first proposed, fabricated, and experimentally demonstrated. The dual-wavelength emitting is achieved by symmetrically introducing two π phase shifts into a chirped four phase-shifted sampled grating cavity. Meanwhile, the beating signal of the dual-wavelength output is stabilized by applying an electro-absorption modulator integrated at the rear of the cavity. Under different grating chirp rates, a series of RF signals from 66.8 GHz to 73.6 GHz with a linewidth of less than 210 kHz is obtained.

A L-band two-section AlGaInAs/InP asymmetric multiple quantum well (QW) passively mode-locked laser has been used to generate a frequency comb with a 100 GHz spacing at a central wavelength of 1610 nm. The comb contains 10 optical lines within a -3 d B bandwidth of 8.05 nm and 34 optical lines within a -20 d B bandwidth of 30 nm. The mode-locked pulse duration was 440 fs. To the best of our knowledge, this is the shortest pulse duration from any directly electrically pumped QW semiconductor mode-locked laser.