Low-cost cultivation of Nannochloropsis oceanica in newly designed photobioreactors and its productivity trends in semi-continuous cultivation under inland outdoor conditions.

Most marine microalgae are typically cultivated in coastal areas due to challenges in inland cultivation. In this 185 days experiment, Nannochloropsis oceanica was semi-continuously cultivated inland using different photobioreactors (PBRs). The newly designed 700-liter (L) PBR exhibited tolerance to seasonal changes compared to the 150-L PBRs. The innovative in-situ oxygen release rate (ORR) measurement method results indicated that ORR was influenced by light intensity and temperature. The optimal temperature range for N. oceanica growth was 14-25 â„ƒ, demonstrated cold tolerance and lipid accumulation at low temperatures. The maximum lipid content in 700-L and 150-L PBRs was 29 % and 28 %, respectively. Based on the average biomass productivity, the price of N. oceanica was $11.89 kg-1 (or $3.35 kg-1 based on maximum biomass productivity), which is cheaper than the current market price of $20.19 kg-1. From results, smaller PBRs at the same hydro electricity price are more cost-effective.

Effects of nitrogen regulation on heavy metal phytoextraction efficiency (Leucaena leucocephala): Application of a nitrogen fertilizer and a fungal agent.

Lead (Pb) and cadmium (Cd) have been identified as the primary contaminants in soil, posing potential health threats. This study aimed to examine the effects of applying a nitrogen fertilizer and a fungal agent Trichoderma harzianum J2 (nitrogen alone, fungi alone, and combined use) on the phytoremediation of soils co-contaminated with Pb and Cd. The growth of Leucaena leucocephala was monitored in the seedling, differentiation, and maturity stages to fully comprehend the remediation mechanisms. In the maturity stage, the biomass of L. leucocephala significantly increased by 18% and 29% under nitrogen-alone (NCK+) and fungal agent-alone treatments (J2), respectively, compared with the control in contaminated soil (CK+). The remediation factors of Pb and Cd with NCK+ treatment significantly increased by 50% and 125%, respectively, while those with J2 treatment increased by 73% and 145%, respectively. The partial least squares path model suggested that the nitrogen-related soil properties were prominent factors affecting phytoextraction compared with biotic factors (microbial diversity and plant growth). This model explained 2.56 of the variation in Cd concentration under J2 treatment, and 2.97 and 2.82 of the variation in Pb concentration under NCK+ and J2 treatments, respectively. The redundancy analysis showed that the samples under NCK+ and J2 treatments were clustered similarly in all growth stages. Also, Chytridiomycota, Mucoromucota, and Ciliophora were the key bioindicators for coping with heavy metals. Overall, a similar remediation mechanism allowed T. harzianum J2 to replace the nitrogen fertilizer to avoid secondary pollution. In addition, their combined use further increased the remediation efficiency.

Optimization and purification of bioproducts from Bacillus velezensis PhCL fermentation and their potential on industrial application and bioremediation.

Bioproduction is considered a promising alternative way of obtaining useful and green chemicals. However, the downstream process of biomolecules has been one of the major difficulties in upscaling the application of bioproducts due to the high purification cost. Acid precipitation is the most common method for purifying biosurfactants from the fermentation broth with high purity. However, the use of strong acids and organic solvents in solvent extraction has limited its application. Hence, in this study, a new strain of Bacillus velezensis PhCL was isolated from phenolic waste, and its production of amylase had been optimized via response surface methodology. After that, amylase and biosurfactant were purified by sequential ammonium sulfate precipitation and the result suggested that even though the purified crude biosurfactant had a lower purification fold compared to the acid precipitation, the yield was higher and both enzymes and biosurfactant also could be recovered for lowering the purification cost. Moreover, the purified amylase and crude biosurfactant were characterized and the results suggested that the purified crude biosurfactant would have a higher emulsion activity and petroleum hydrocarbon removal rate compared to traditional surfactants. This study provided another approach for purifying bioactive compounds including enzymes and biosurfactants from the same fermentation broth and further explored the potential of the crude purified biosurfactant in the bioremediation of polycyclic aromatic hydrocarbons and petroleum hydrocarbons.

Characterization of Potential Virulence, Resistance to Antibiotics and Heavy Metals, and Biofilm-Forming Capabilities of Soil Lignocellulolytic Bacteria.

Soil bacteria participate in self-immobilization processes for survival, persistence, and production of virulence factors in some niches or hosts through their capacities for autoaggregation, cell surface hydrophobicity, biofilm formation, and antibiotic and heavy metal resistance. This study investigated potential virulence, antibiotic and heavy metal resistance, solvent adhesion, and biofilm-forming capabilities of six cellulolytic bacteria isolated from soil samples: Paenarthrobacter sp. MKAL1, Hymenobacter sp. MKAL2, Mycobacterium sp. MKAL3, Stenotrophomonas sp. MKAL4, Chryseobacterium sp. MKAL5, and Bacillus sp. MKAL6. Strains were subjected to phenotypic methods, including heavy metal and antibiotic susceptibility and virulence factors (protease, lipase, capsule production, autoaggregation, hydrophobicity, and biofilm formation). The effect of ciprofloxacin was also investigated on bacterial susceptibility over time, cell membrane, and biofilm formation. Strains MKAL2, MKAL5, and MKAL6 exhibited protease and lipase activities, while only MKAL6 produced capsules. All strains were capable of aggregating, forming biofilm, and adhering to solvents. Strains tolerated high amounts of chromium, lead, zinc, nickel, and manganese and were resistant to lincomycin. Ciprofloxacin exhibited bactericidal activity against these strains. Although the phenotypic evaluation of virulence factors of bacteria can indicate their pathogenic nature, an in-depth genetic study of virulence, antibiotic and heavy metal resistance genes is required.

A comparative study of Cellulomonas sp. and Bacillus sp. in utilizing lignocellulosic biomass as feedstocks for enzyme production.

The demand for enzymes is increasing continuously due to their applications in various avenues. The pectin-hydrolyzing bacteria, Cellulomonas sp. and Bacillus sp., isolated from forest soil have the potential to produce industrially important enzymes (pectinase, PGase, Cellulase, and xylanase). However, these bacteria have different optimal cultural conditions for pectinase production. The optimal cultural conditions for Cellulomonas sp. were room temperature (25-26℃), pH 7, 1% inoculum volume, and 1.5% citrus pectin with 8.82 ± 0.92 U/mL pectinase activity. And Bacillus sp. illustrated the highest pectinase activity (12.35 ± 0.72 U/mL) at room temperature, pH 10, 1% inoculum volume, and 1.5% pectin concentration. Among the different agro-wastes, the orange peel was found to be the best substrate for pectinase, PGase, and cellulase activity whereas barley straw for xylanase activity. Further, Cellulomonas sp. and Bacillus sp. illustrated higher pectinase activity from commercial pectin compared to orange peel showing their preference for commercial citrus pectin. In addition, the optimization by the Box-Behnken design increased pectinase activity for Cellulomonas sp., while a noticeable increase in activity was not observed in Bacillus sp. Besides, all the agro-wastes exploited in this study can be used for pectinase, PGase, and xylanase production but not cellulase. The study revealed that each bacteria has its specific optimal conditions and there is a variation in the capacity of utilizing the various lignocellulosic biomass.

Biomass-Degrading Enzyme(s) Production and Biomass Degradation by a Novel Streptomyces thermocarboxydus.

Modern society has a great challenge to decrease waste and minimize the adverse effects of wastes on the economy, environment, and individual health. Thus, this study focuses on the use of eight agro-wastes (banana peel, barley straw, canola straw, pomegranate peel, orange peel, pumpkin pulp+seeds, maple leaf, and brewer's spent grains) by a novel bacterium (Streptomyces thermocarboxydus) for enzymes production. Further, the study explored the subsequent degradation of those wastes by the bacterium. This bacterium was isolated from forest soil and identified as Streptomyces thermocarboxydus by 16S rRNA sequence analysis. The biodegrading capability of S. thermocarboxydus was determined by observing the clear zone around the colony cultured on the agar plate containing the different biomasses as sole carbon sources and calculating the substrate degradation ratios. Furthermore, scanning electron microscopy images of eight agro-wastes before and after bacterial treatment and weight loss of agro-wastes revealed the bacterium degraded the biomasses. The different trends of enzyme activities were observed for various wastes, and the maximum activity depended on the type of agro-wastes. Overall, S. thermocarboxydus was found to be a potential candidate for pectinase and xylanase production. The enzyme production varies with the concentration of the biomasses.

Optimization of cultural conditions for pectinase production by Streptomyces sp. and characterization of partially purified enzymes.

The cultural parameters of Streptomyces sp. for pectinase production were optimized using the Box-Behnken design. The maximum pectinase production was obtained after 58 hours at 35℃ and pH 7 upon submerged fermentation in yeast extract-containing media. The enzymes were partially purified with acetone precipitation and the analysis by SDS-PAGE and zymogram revealed that Streptomyces sp. produced two pectinases with molecular weights of about 25 and 75 kDa. The pectinase activity was detected in a wide range of temperatures (30℃ to 80℃) and pH (3 to 9) with maximum pectinase activities observed at 70℃ and pHs 5 and 9. The enzymes retained about 30 to 40% of their activities even after incubating the enzyme at different temperatures for 120 mins. The pectinase activities of Streptomyces sp. were enhanced in the media containing 1.5% pectin, 1% casein as a nitrogen source, 0.5 mM MgSO4, and 5 mM NaCl. Further, the addition of Tween-20, amino acids, and vitamins to the media also enhanced the pectinase activity. Moreover, the bacterium illustrated the ability to decolorize crystal violet dye efficiently. The decolorization rate ranged from 39.29 to 53.75% showing the highest bacterial decolorization in the media containing 2mg/mL crystal violet at 144 hours. Therefore, the bacterium has the potential in treating wastewater produced by industries like textile industries.

Optimization of multiple enzymes production by fermentation using lipid-producing Bacillus sp.

The present study identified the pectinase-producing bacterium isolated from the contaminated broth as Bacillus sp. on 16S rDNA sequence analysis. The bacterium illustrated water-like droplets on the colony grown on the Sabouraud dextrose agar plate. It also exhibited multi-enzymes activities, such as pectinase, polygalacturonase, xylanase, and cellulase by using various agro-wastes as low-cost substrates. The orange peel was observed to be the best substrate among the agro-wastes used for maximum multi-enzymes (pectinase, polygalacturonase, xylanase, and cellulase). However, the bacterium demonstrated its capability to produce different enzymes according to the different substrates/agro-wastes used. The Plackett-Burman design was used to determine the essential influencing factors, while the Box Behnken design response surface methodology was for optimizing cultural conditions. At their optimal conditions (40°C incubation temperature, 24 h of incubation period, 1% w/v orange peel, and 2% v/v inoculum volume), the bacterium exhibited the maximum pectinase (9.49 ± 1.25 U/ml) and xylanase (16.27 ± 0.52 U/ml) activities. Furthermore, the study explored the ability of the bacterium to produce bacterial lipids and observed about 25% bacterial lipid content on a dry weight basis. Therefore, the bacterium is a good candidate for producing important multi-enzymes and subsequent agro-waste degradation controlling the environment, and facilitating waste management. Also, the bacterium can be a potential feedstock in producing renewable biofuel.

Characterization of Cellulose-Degrading Bacteria Isolated from Soil and the Optimization of Their Culture Conditions for Cellulase Production.

The characterization of bacteria with hydrolytic potential significantly contributes to the industries. Six cellulose-degrading bacteria were isolated from mixture soil samples collected at Kingfisher Lake and the University of Manitoba campus by Congo red method using carboxymethyl cellulose agar medium and identified as Paenarthrobacter sp. MKAL1, Hymenobacter sp. MKAL2, Mycobacterium sp. MKAL3, Stenotrophomonas sp. MKAL4, Chryseobacterium sp. MKAL5, and Bacillus sp. MKAL6. Their cellulase production was optimized by controlling different environmental and nutritional factors such as pH, temperature, incubation period, substrate concentration, nitrogen, and carbon sources using the dinitrosalicylic acid and response surface methods. Except for Paenarthrobacter sp. MKAL1, all strains are motile. Only Bacillus sp. MKAL6 was non-salt-tolerant and showed gelatinase activity. Sucrose enhanced higher cellulase activity of 78.87 ± 4.71 to 190.30 ± 6.42 U/mL in these strains at their optimum pH (5-6) and temperature (35-40 °C). The molecular weights of these cellulases were about 25 kDa. These bacterial strains could be promising biocatalysts for converting cellulose into glucose for industrial purposes.

Chloroplast genome analysis of Chrysotila dentata.

Chrysotila dentata is an ecologically important marine alga contributing to the coccolith formation. In this study, a complete chloroplast (cp DNA) genome of Chrysotila dentata was sequenced by using Illumina Hiseq and was analyzed with the help of a bioinformatics tool CPGAVAS2. The circular chloroplast genome of Chrysotila dentata has a size of 109,017 bp with two inverted repeats (IRs) regions (4513 bp each) which is a common feature in most land plants and algal species. The Chrysotila dentata cp genome consists of 61 identified protein-coding genes, 30 tRNA genes and 6 rRNAs with 21 microsatellites. The phylogenetic relationship with other select algal species revealed a close phylogeny of Chrysotila dentata with Phaeocystis antarctica. This is the first report of the cp genome analysis of genus Chrysotila and the results from this study will be helpful for understanding the genetic structure and function of chloroplast in other species of Chrysotila.

Energy-water and seasonal variations in climate underlie the spatial distribution patterns of gymnosperm species richness in China.

Studying the pattern of species richness is crucial in understanding the diversity and distribution of organisms in the earth. Climate and human influences are the major driving factors that directly influence the large-scale distributions of plant species, including gymnosperms. Understanding how gymnosperms respond to climate, topography, and human-induced changes is useful in predicting the impacts of global change. Here, we attempt to evaluate how climatic and human-induced processes could affect the spatial richness patterns of gymnosperms in China. Initially, we divided a map of the country into grid cells of 50 × 50 km2 spatial resolution and plotted the geographical coordinate distribution occurrence of 236 native gymnosperm taxa. The gymnosperm taxa were separated into three response variables: (a) all species, (b) endemic species, and (c) nonendemic species, based on their distribution. The species richness patterns of these response variables to four predictor sets were also evaluated: (a) energy-water, (b) climatic seasonality, (c) habitat heterogeneity, and (d) human influences. We performed generalized linear models (GLMs) and variation partitioning analyses to determine the effect of predictors on spatial richness patterns. The results showed that the distribution pattern of species richness was highest in the southwestern mountainous area and Taiwan in China. We found a significant relationship between the predictor variable set and species richness pattern. Further, our findings provide evidence that climatic seasonality is the most important factor in explaining distinct fractions of variations in the species richness patterns of all studied response variables. Moreover, it was found that energy-water was the best predictor set to determine the richness pattern of all species and endemic species, while habitat heterogeneity has a better influence on nonendemic species. Therefore, we conclude that with the current climate fluctuations as a result of climate change and increasing human activities, gymnosperms might face a high risk of extinction.

Variation of body temperature of active amphibians along elevation gradients in eastern Nepal Himalaya.

Understanding the thermal ecology of active amphibians, as well as its relationship with habitat and environmental features, is a central theme in ecology. However, this topic has been poorly studied in eastern Himalaya, which is a global biodiversity hotspot. To bridge this gap, we investigated how the body temperatures of active amphibians varied along an elevation gradient in the Arun and Tamor River catchments in eastern Nepal Himalaya in the present study. Amphibian assemblages were sampled from May to July in both 2014 and 2015 using nocturnal time-constrained visual encounter surveys, and the body temperature of each individual was directly measured using a digital infrared thermometer in the field. A combination of linear regression and hierarchical partitioning analyses was used to determine the effects of elevation and environmental variables on the body temperatures of active amphibians. In total, the body temperatures of 599 amphibian individuals belonging to 28 species from six families were recorded. Our results indicated that amphibian body temperature exhibited monotonically declining trends with increasing elevations in eastern Nepal Himalaya. Interestingly, this tread was much more pronounced in subtropical (lowland) areas than in warm and cool temperate regions. Inter- and intraspecies variations in body temperature were large, which can be attributed to distinct habitat utilization among species and the change in vegetation cover in different bioclimatic zones. Among all environmental variables, substrate temperature and water temperature were the best predictors of the amphibian body temperature. Overall, this study revealed amphibian body temperature patterns along an elevation gradient in eastern Nepal Himalaya, which were principally driven by temperature-related environmental factors. We believe our results can provide important information on amphibian physiological traits, which may help ecologists predict their responses to future climate change and formulate protection strategies.

Sorrel Extract Reduces Oxidant Production in Airway Epithelial Cells Exposed to Swine Barn Dust Extract In Vitro.

Exposure to hog barn organic dust contributes to occupational lung diseases, which are mediated by inflammatory and oxidative stress pathways. Isoprostanes-a family of eicosanoids produced by oxidation of phospholipids by oxygen radicals-are biomarkers of pulmonary oxidative stress. Importantly, 8-isoprostane has been implicated as a key biomarker and mediator of oxidative stress because it is a potent pulmonary vasoconstrictor. Antioxidants found in fruits and vegetables hold promise for preventing or reducing effects of oxidative stress-related diseases including chronic bronchitis and chronic obstructive pulmonary disease (COPD). Here, we investigated 8-isoP and oxidant production by organic dust-exposed airway epithelial cells and the inhibitory effects of an extract from calyces of the sorrel plant, Hibiscus sabdariffa, on oxidant-producing pathways. Confluent cultures of normal human tracheobronchial epithelial cells were pretreated or not with 1% sorrel extract prior to 5% dust extract (DE) exposure. Following DE treatments, live cells, cell-free supernatants, or cell extracts were evaluated for the presence of 8-isoprostane, superoxide, hydrogen peroxide, nitric oxide, hydroxyl radical, peroxynitrite, and catalase activity to evaluate sorrel's inhibitory effect on oxidative stress. The well-known radical scavenging antioxidant, N-acetyl cysteine (NAC), was used for comparisons with sorrel. DE exposure augmented the production of all radicals measured including 8-isoprostane (p value < 0.001), which could be inhibited by NAC or sorrel. Among reactive oxygen and nitrogen species generated in response to DE exposure, sorrel had no effect on H2O2 production and NAC had no significant effect on NO· production. The observations reported here suggest a possible role for sorrel in preventing 8-isoprostane and oxidant-mediated stress responses in bronchial epithelial cells exposed to hog barn dust. These findings suggest a potential role for oxidative stress pathways in mediating occupational lung diseases and antioxidants within sorrel and NAC in reducing dust-mediated oxidative stress within the airways of exposed workers.

Amphibian community structure along elevation gradients in eastern Nepal Himalaya.

BACKGROUND: Species richness and composition pattern of amphibians along elevation gradients in eastern Nepal Himalaya are rarely investigated. This is a first ever study in the Himalayan elevation gradient, the world's highest mountain range and are highly sensitive to the effects of recent global changes. The aim of the present study was to assess amphibian community structure along elevation gradients and identify the potential drivers that regulate community structures. Amphibian assemblages were sampled within 3 months in both 2014 and 2015 (from May to July) using nocturnal time constrained and acoustic aids visual encounter surveys. In total, 79 transects between 78 and 4200 m asl were sampled within 2 years field work. A combination of polynomial regression, generalized linear models, hierarchical partitioning and canonical correspondence analysis were used to determine the effects of elevation and environmental variables on species richness, abundance, and composition of amphibian communities. RESULTS: Species richness and abundance declined linearly with increasing elevation, which did not support the Mid-Domain Model. Among all the environmental variables, elevation, surface area and humidity were the best predictors of species richness, abundance and composition of amphibians. The majority of amphibian species had narrow elevation ranges. There was no significant correlation between species range size and elevation gradients. However, body size significantly increased along elevation gradients, indicating that Bergmann's rule is valid for amphibians in eastern Nepal Himalaya. CONCLUSIONS: This study indicates that eastern Nepal Himalaya is a hotspot in amphibian diversity, and it should be served as a baseline for management and conservation activities.

mtDNA analysis confirms the endangered Kashmir musk deer extends its range to Nepal.

Musk deer Moschus spp. are endemic to the high mountain forests of central Asia. The taxonomic status of musk deer in the central and western Himalayas is poorly understood. We investigated the phylogenetic relationship of musk deer from the central and western Himalayas based on mitochondrial genomic data of Cytochrome b (380 bps) and D-loop (1000 bps). Our results distinguished two divergent lineages using higher bootstrap support (bs) values from the Maximum likelihood and Bayesian posterior probabilities (bpp). Both the Manang and Kaski lineages from central Nepal are confirmed as Himalayan musk deer Moschus leucogaster and represent a species complex widespread throughout the central and eastern Himalayan region. The musk deer Mustang lineage was confirmed as Kashmir musk deer Moschus cupreus and has wide distribution in the western Himalayas (from central Nepal to Afghanistan). Our analysis validates that Kashmir musk deer is a genetically distinct species and it clarifies that Himalayan musk deer and Kashmir musk deer are confirmed instead of Alpine musk deer Moschus chrysogaster which has been previously described from the southern parts of Himalayas of Nepal, India and Pakistan.

Predicting the potential distribution of the endangered red panda across its entire range using MaxEnt modeling.

An upsurge in anthropogenic impacts has hastened the decline of the red panda (Ailurus fulgens). The red panda is a global conservation icon, but holistic conservation management has been hampered by research being restricted to certain locations and population clusters. Building a comprehensive potential habitat map for the red panda is imperative to advance the conservation effort and ensure coordinated management across international boundaries. Here, we use occurrence records of both subspecies of red pandas from across their entire range to build a habitat model using the maximum entropy algorithm (MaxEnt 3.3.3k) and the least correlated bioclimatic variables. We found that the subspecies have separate climatic spaces dominated by temperature-associated variables in the eastern geographic distribution limit and precipitation-associated variables in the western distribution limit. Annual precipitation (BIO12) and maximum temperature in the warmest months (BIO5) were major predictors of habitat suitability for A. f. fulgens and A. f. styani, respectively. Our model predicted 134,975 km2 of red panda habitat based on 10 percentile thresholds in China (62% of total predicted habitat), Nepal (15%), Myanmar (9%), Bhutan (9%), and India (5%). Existing protected areas (PAs) encompass 28% of red panda habitat, meaning the PA network is currently insufficient and alternative conservation mechanisms are needed to protect the habitat. Bhutan's PAs provide good coverage for the red panda habitat. Furthermore, large areas of habitat were predicted in cross-broader areas, and transboundary conservation will be necessary.

Phylogenetic surveys on the newt genus Tylototriton sensu lato (Salamandridae, Caudata) reveal cryptic diversity and novel diversification promoted by historical climatic shifts.

Global climatic transitions and Tibetan Plateau uplifts are hypothesized to have profoundly impacted biodiversity in southeastern Asia. To further test the hypotheses related to the impacts of these incidents, we investigated the diversification patterns of the newt genus Tylototriton sensu lato, distributed across the mountain ranges of southeastern Asia. Gene-tree and species-tree analyses of two mitochondrial genes and two nuclear genes revealed five major clades in the genus, and suggested several cryptic species. Dating estimates suggested that the genus originated in the early-to-middle Miocene. Under different species delimitating scenarios, diversification analyses with birth-death likelihood tests indicated that the genus held a higher diversification rate in the late Miocene-to-Pliocene era than that in the Pleistocene. Ancestral area reconstructions indicated that the genus originated from the northern Indochina Peninsula. Accordingly, we hypothesized that the Miocene Climatic Transition triggered the diversification of the genus, and the reinforcement of East Asian monsoons associated with the stepwise uplifts of the Tibetan Plateau promoted the radiation of the genus in southeastern Asia during the Miocene-to-Pliocene period. Quaternary glacial cycles likely had limited effects on speciation events in the genus, but mainly had contributions on their intraspecific differentiations.

A new species of the genus Microhyla (Anura: Microhylidae) from Eastern Nepal.

A new species of the genus Microhyla is described from Jamun Khadi, Jhapa district of eastern Nepal, based on molecular and morphological comparisons. This species is the sister taxon of Microhyla ornata and can be distinguished by a unique vocalization, morphology and molecular phylogeny. The uncorrected genetic divergences based on rRNA gene between the new species and its closest congeners, M. nilphamariensis, M. ornata and M. rubra were 5.34%, 6.67%, and 8.31%, respectively. The new species, Microhyla taraiensis sp. nov., is distinguished from each other of Microhyla by a combination of the following morphological characters: (1) relatively larger body size (SVL ranges 19.9-20.3 mm, n = 4 in the males and 22.1-24.9 mm, n = 3 in the females); (2) dorsal surface of head and body with light red dots; (3) toes webbing poorly developed or absent; (4) a large round inner metacarpal tubercle; and an (5) elongated outer metacarpal tubercle. In addition, our study also provides a new record of Microhyla nilphamariensis from Nepal.

Virucidal Activity of Fogged Chlorine Dioxide- and Hydrogen Peroxide-Based Disinfectants against Human Norovirus and Its Surrogate, Feline Calicivirus, on Hard-to-Reach Surfaces.

Human norovirus (NoV) is the leading cause of foodborne illnesses in the United States. Norovirus is shed in high numbers in the feces and vomitous of infected individuals. Contact surfaces contaminated with bodily fluids harboring infectious virus particles serve as vehicles for pathogen transmission. Environmental stability of NoV and its resistance to many conventional disinfectants necessitate effective inactivation strategies to control the spread of virus. We investigated the efficacy of two commercial disinfectants, hydrogen peroxide (7.5%) and a chlorine dioxide (0.2%)-surfactant-based product using a fogging delivery system against human NoV GI.6 and GII.4 Sydney strains as well as the cultivable surrogate, feline calicivirus (FCV) dried on stainless steel coupons. Log10 reductions in human NoV and FCV were calculated utilizing RNase RT-qPCR and infectivity (plaque) assay, respectively. An improved antiviral activity of hydrogen peroxide as a function of disinfectant formulation concentration in the atmosphere was observed against both GII.4 and FCV. At 12.4 ml/m3, hydrogen peroxide achieved a respective 2.5 ± 0.1 and 2.7 ± 0.3 log10 reduction in GI.6 and GII.4 NoV genome copies, and a 4.3 ± 0.1 log10 reduction in infectious FCV within 5 min. At the same disinfectant formulation concentration, chlorine dioxide-surfactant-based product resulted in a respective 1.7 ± 0.2, 0.6 ± 0.0, and 2.4 ± 0.2 log10 reduction in GI.6, GII.4, and FCV within 10 min; however, increasing the disinfectant formulation concentration to 15.9 ml/m3 negatively impacted its efficacy. Fogging uniformly delivered the disinfectants throughout the room, and effectively decontaminated viruses on hard-to-reach surfaces. Hydrogen peroxide delivered by fog showed promising virucidal activity against FCV by meeting the United States EPA 4-log10 reduction criteria for an anti-noroviral disinfectant; however, fogged chlorine dioxide-surfactant-based product did not achieve a 4-log10 inactivation. Future investigation aimed at optimizing decontamination practices is warranted.

Targeting MicroRNA in Cancer Using Plant-Based Proanthocyanidins.

Proanthocyanidins are oligomeric flavonoids found in plant sources, most notably in apples, cinnamon, grape skin and cocoa beans. They have been also found in substantial amounts in cranberry, black currant, green tea, black tea and peanut skins. These compounds have been recently investigated for their health benefits. Proanthocyanidins have been demonstrated to have positive effects on various metabolic disorders such as inflammation, obesity, diabetes and insulin resistance. Another upcoming area of research that has gained widespread interest is microRNA (miRNA)-based anticancer therapies. MicroRNAs are short non-coding RNA segments, which plays a crucial role in RNA silencing and post-transcriptional regulation of gene expression. Currently, miRNA based anticancer therapies are being investigated either alone or in combination with current treatment methods. In this review, we summarize the current knowledge and investigate the potential of naturally occurring proanthocyanidins in modulating miRNA expression. We will also assess the strategies and challenges of using this approach as potential cancer therapeutics.