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Energy conservation in microorganisms is classically categorized into respiration and fermentation; however, recent work shows some species can use mixed or alternative bioenergetic strategies. We explored the use of extracellular electron transfer for energy conservation in diverse lactic acid bacteria (LAB), microorganisms that mainly rely on fermentative metabolism and are important in food fermentations. The LAB Lactiplantibacillus plantarum uses extracellular electron transfer to increase its NAD+/NADH ratio, generate more ATP through substrate-level phosphorylation, and accumulate biomass more rapidly. This novel, hybrid metabolism is dependent on a type-II NADH dehydrogenase (Ndh2) and conditionally requires a flavin-binding extracellular lipoprotein (PplA) under laboratory conditions. It confers increased fermentation product yield, metabolic flux, and environmental acidification in laboratory media and during kale juice fermentation. The discovery of a single pathway that simultaneously blends features of fermentation and respiration in a primarily fermentative microorganism expands our knowledge of energy conservation and provides immediate biotechnology applications.

Real-time process metrics are standard for the majority of fermentation-based industries but have not been widely adopted by the wine industry. In this study, replicate fermentations were conducted with temperature as the main process parameter and assessed via in-line Oxidation Reduction Potential (ORP) probes and at-line profiling of phenolics compounds by UV-Vis spectroscopy. The California and Oregon vineyards used in this study displayed consistent vinification outcomes over five vintages and are representative of sites producing faster- and slower-fermenting musts. The selected sites have been previously characterized by fermentation kinetics, elemental profile, phenolics, and sensory analysis. ORP probes were integrated into individual fermentors to record how ORP changed throughout the fermentation process. The ORP profiles generally followed expected trends with deviations revealing previously undetectable process differences between sites and replicates. Site-specific differences were also observed in phenolic and anthocyanin extraction. Elemental composition was also analyzed for each vineyard, revealing distinctive profiles that correlated with the fermentation kinetics and may influence the redox status of these wines. The rapid ORP responses observed related to winemaking decisions and yeast activity suggest ORP is a useful process parameter that should be tracked in addition to Brix, temperature, and phenolics extraction for monitoring fermentations.

Dedicated lactation rooms are a modern development as mothers return to work while still providing breastmilk to their absent infants. This study describes the built environment microbiome of lactation rooms and daycares, and explores the influence of temperature and humidity on the microbiome of lactation rooms. Sterile swabs were used to collect samples from five different sites in lactation rooms at University of California, Davis and from five different sites in daycares located in Davis, California. DNA from the swabs was extracted and the V4 region of the 16S rRNA gene was sequenced using Illumina MiSeq. Temperature and relative humidity data were collected on a subset of the lactation rooms. Sampled lactation rooms could be either dedicated lactation rooms or could also serve other functions (e.g., combined lactation room and restroom lounge). The majority of sequence reads were identified as belonging to family Moraxellaceae, with 73% of all reads included in analysis identified as an unknown species of Acinetobacter. Alpha diversity was analyzed using the Shannon index, while beta diversity was analyzed using unweighted and weighted UniFrac distance. The Jaccard distance was used to measure amount of change at sampling locations between time points for analysis of the impact of temperature and humidity on the microbiome. There were significant differences in the beta diversity of the microbiome of lactation rooms by room type. There were also significant differences in the beta diversity of the microbiome by sample collection location. There were no significant differences in either alpha or beta diversity associated with room temperature or humidity. Additional studies are needed to understand if the differences in lactation room type may result in differences in the breastmilk microbiome of milk collected in those rooms, and to what extent any such differences may influence the infant microbiome.

One-dimensional array generators with seven to fifteen spots are designed by the method of virtual sources in combination with simulated-annealing optimization. Continuous surface-relief grating array generators and their discretized versions are analyzed with rigorous diffraction theory, and the results are compared with those obtained from Fourier-optics theory. The array-generator designs have high diffraction efficiency and good uniformity.

Aproposed method to enhance 13 femtosecond 625 nanometer wavelength pulses to twice these rates as well as produce 11 fs 312 nm ultraviolet pulses and factor ten picoJoules energies uses a 2.5 micrometer thin film. The thin medium is a nonlinear poled polymeric film with very small group velocity mismatch for enhancement purposes. Results support the use of poled polymer film for enhancement of pulse rates since this medium possess characteristics which make them suited for nonlinear optical applications.

An iterative calculation method for determining the propagation constant of modes in multilayer planar waveguides is presented. The method, which is based on the transfer matrix analysis technique, is a second-order convergent algorithm and is capable of evaluating the transfer matrix using only four values of the longitudinal propagation constant. To test its reliability, this method is employed in the analysis of two sample problems. Results indicate that the new method is more reliable than traditional iterative techniques.

The transfer function of an external modulator is the critical factor that determines the spurious free dynamic range, signal power gain, and noise figure of a wide-band analog RF-photonic link. We present an in-line asymmetric directional coupler modulator with distributed optical loss capable of providing a transfer function linearized to the fourth order for multi-octave bandwidths. This modulator compares favorably with multiple modulator suboctave linearization techniques consisting of series symmetric directional coupler and series Mach-Zehnder modulators and superoctave parallel Mach-Zehnder, and cascaded sections containing series Mach-Zehnder/symmetric directional coupler modulators. The optimum bias point for the asymmetric directional coupler modulator is determined by device dimensions and material parameters with relative insensitivity to errors introduced during fabrication. Optical insertion loss imposes significant limitations on modulator performance. An implementation of an in-line asymmetric directional coupler modulator is discussed that eliminates excess loss due to fiber coupling in order to achieve a large RF power gain and competitive noise figure compared to the linearization configurations. Index Terms - Coupled mode analysis, electrooptic devices, electrooptic modulation, microwave communication, modulation, nonlinear distortion, optical fiber communication, optical fiber couplers, optical waveguide components.

The supramolecular organization of the two major plant polysaccharides, glucose and starch, remains poorly understood, despite decades of investigation. Almost all recent advances in the field have relied on methods requiring crystalline samples: as a consequence, relatively little is known about the so-called amorphous regions of either cellulose or starch, or the relationship between crystalline and noncrystalline regions. Parametric nonlinear optical properties such as second harmonic generation, sum frequency generation vibrational spectroscopy, and third harmonic generation are ideally suited for studying both crystalline and amorphous regions in intact samples. In this paper we review the nonlinear optical properties of cellulose and starch in the context of their molecular and supramolecular structure. We speculate on specific questions that could be addressed with this approach, and how they might contribute to a better understanding of common structural themes in biological macromolecules. [ABSTRACT FROM AUTHOR]