Biology subjects

Pendyala, B.

Publications and source records attributed to Pendyala, B..

10 recordsLinked to original sources

bioRxiv2022

Performance Assessment of an Ultraviolet Light Emitting Semi-Conductor Device in Treating Apple Juice: Microbial Inactivation and Biochemical Assessment Study

Inactivation of Listeria monocytogenes ATCC 19115 and Salmonella enterica serovar Muenchen ATCC BAA 1764 by a light emitting diodes (LED) operating at 279 nm was investigated. In addition, this investigation assessed the poly-phenolic and vitamin content of UV irradiated apple juice (AJ). Specific concentrations of bacteria were inoculated in AJ and irradiated at the designated UV doses of 0 to 10 mJ{middle dot}cm-2 for Salmonella Muenchen and 0 to 12 mJ{middle dot}cm-2 for Listeria monocytogenes.Results show that UV-C irradiation effectively inactivated pathogenic microbes in AJ. The log reduction kinetics of microorganisms followed log-linear and with higher R2 (>0.95). The D10 values of 3.50 and 3.56 mJ{middle dot}cm-2 were obtained from the inactivation of Salmonella Muenchen, and Listeria monocytogenes in apple juice. In addition, quantifiable UV-C doses ranging from 0 to 160 mJ{middle dot}cm-2 were also delivered to AJ and polyphenols and vitamins were profiled. LC-MS/MS analysis was conducted to assess the stability of polyphenols or vitamins in UV-C exposed AJ. The polyphenol and vitamin results demonstrated that UV-C irradiation in AJ can cause significant reductions (p<0.05) if not properly delivered. Chlorogenic acid was reduced to 56%, at 80 mJ/cm2 whereas 12% reduction was observed at 40 mJ/cm2. Choline was observed to be relatively stable as a function of UV-C dosage. In contrast thiamine was significantly reduced at higher doses. In addition, Epicatechin was significantly reduced at high exposure doses. In contrast minor changes were observed at 40 mJ/cm2. The results from this study imply that adequate log reduction of pathogens is achievable in AJ and suggest significant potential of using LED devices for UV-C treatment of highly turbid fluids.

microbiology↗

bioRxiv2022

Effect of germicidal short wave-length ultraviolet light on the polyphenols, vitamins, and microbial inactivation in highly opaque apple juice

The aim of this investigation was to study the efficacy of UV-C light emitting diode system (LED) operating at 263 nm for the inactivation of Listeria monocytogenes and Escherichia coli O157:H7. Specified concentrations of bacteria were inoculated in apple juice and irradiated at the designated UV doses of 0 to 15 mJ{middle dot}cm-2. In addition, UV irradiation doses ranging from 0 to 160 mJ{middle dot}cm-2 were also delivered to apple juice and polyphenols and vitamins were profiled. LC-MS/MS analysis was conducted to assess the stability of polyphenols or vitamins in UV-C exposed apple juice. The polyphenol and vitamin results demonstrated that UV-C irradiation in apple juices at relevant commercial UV doses induced significant reductions in the concentrations of selected polyphenols and vitamins, p<0.05. Ascorbic acid was reduced to 32%, at 160 mJ/cm2 whereas 17% reduction was observed at 40 mJ/cm2. Riboflavin was observed to be relatively stable. Epicatechin and chlorogenic was significantly reduced at high exposure doses. In contrast minor changes were observed at 40 mJ/cm2. Results show that UV-C irradiation effectively inactivated pathogenic microbes in apple juice. The log reduction kinetics of microorganisms followed log-linear and with higher R2 (>0.95) and low RMSE values. The D10 values of 4.16 and 3.84 mJ{middle dot}cm-2 were obtained from the inactivation of Escherichia coli, and Listeria monocytogenes in apple juice. The results from this study imply that adequate log reduction of pathogens is achievable in apple juice and suggest significant potential for UV-C treatment of other liquid foods.

microbiology↗

bioRxiv2022

Evaluating UV-C sensitivity of Coxiella burnetii in Skim Milk using a Bench-Scale Collimated Beam System and Comparative Study with High-Temperature Short-Time Pasteurization

Coxiella burnetii is a zoonotic Gram-negative obligate intracellular bacterial pathogen and the causative agent of Query (Q) fever in humans. Contamination of milk by C. burnetii as a consequence of livestock infection is a significant public health concern. Effective methods to inactivate C. burnetii in milk is a critical aspect of food safety. In this study, we measured optical light attenuation factors; absorption, scattering, and reflection of skim milk (SM) and considered for evaluation of delivered UV dose under stirred conditions. The accuracy of the method followed for the estimation of delivered UV dose in SM was verified by comparative studies of Escherichia coli ATCC 25922 inactivation in phosphate buffer (transparent fluid), and humic acid (opaque fluid). Absorption, scattering coefficient, and the reflectance of SM at 254 nm was measured as 19 {+/-} 0.3/cm. 26 {+/-} 0.5/cm and 10.6 %, respectively. SM inoculated with C. burnetii was irradiated using a collimated beam device equipped with a low-pressure UV-C254 nm lamp at doses from 0 - 12 mJ{middle dot}cm-2. Results showed a log-linear inactivation of C. burnetii in SM with UV-C sensitivity (D10) value of 4.1 {+/-} 0.04 mJ{middle dot}cm-2. Similar inactivation kinetics was observed with Salmonella enterica serovar Muenchen ATCC BAA 1674 in SM and thereby suggested as a suitable surrogate to C. burnetii for pilot scale UV-C processing studies of SM.

microbiology↗

bioRxiv2022

In silico screening of novel senolytic compounds from natural food sources

More than 23% of todays population suffers from age-associated diseases such as arthritis, cancer, heart disease, and more. The ongoing economic impact of these diseases has been in the billions of dollars worldwide with no clear solution to date. This study addresses the underlying cause of these diseases by identifying the compounds that potentially eliminate senescent cells. Existing senolytic drugs are not abundantly found in nature, reducing accessibility. Hence, over 70,000 natural compounds available in the Canadian Food Database were used to screen penitential senolytic compounds that block PI3K{gamma}, reactivating apoptotic processes in senescent cells. Molecular docking results revealed 23 natural compounds that blocks the PI3K{gamma}. Out of 23 compounds, Cianidanol, Ellagic acid, Eriodictyol, Kaempferol and Cyanidin were found abundantly in food sources range from 85 to 735 mg/100 g. These compounds are up to 46 times more abundant in foods than proven senolytic drug Fisetin. Further, molecular dynamics results showed ligand stability for 4 nanoseconds with PI3K{gamma}. The five compounds are proven to eliminate cancerous cells, have the potential to prevent age-related diseases, and could even slow down natural aging.

bioinformatics↗

bioRxiv2022

Inactivation of B. cereus Spores in Whole Milk and Almond Milk by Novel Serpentine Path Coiled Tube UV-C System

A novel continuous thin-film (1.59 mm) serpentine path coiled tube (SPCT) UV system operating at 254 nm wavelength was designed and compared with flow field distribution of whole milk with helical path coiled tube (HPCT) UV system using computational fluid dynamics. The results revealed efficient velocity magnitude distribution at serpentine bend geometric locations of the SPCT UV system. Further in this study, we evaluated B. cereus Spores inactivation in whole milk (WM) and almond milk (AM) using the developed SPCT UV system. Experimental data showed that > 4 log reduction of spores was achieved after six and ten passes of WM and AM at a flow rate of 70 and 162 mL/min, respectively. The biodosimetry method was used to verify the delivered reduction equivalent fluence (REF) and reported as 33 {+/-} 0.73 and 36.5 {+/-} 1.9 mJ/cm2. We noticed no significant effect on lipid oxidation and volatiles profile (p > 0.05) up to delivered REF of 60 mJ/cm2. This study demonstrated that high levels of inactivation of B. cereus spores could be feasible with minimal impact on product quality by UV-C processing of dairy and non-dairy opaque scattering fluids.

microbiology↗

bioRxiv2022

Pilot scale study on UV-C inactivation of bacterial endospores and virus particles in whole milk: evaluation of system efficiency and product quality

UV-C processing of whole milk (WM) using a designed pilot scale Dean flow system was conducted at flow rates (11.88, 23.77, and 47.55 gph), Reynolds number ranges from 2890-11562 and the Dean number (at curved region) calculated as (648-2595) to inactivate bacterial endospores and virus particles. Biodosimetry studies were conducted to quantify the reduction equivalent fluence at selected experimental conditions. Results revealed that the fluence distribution improved as flow rate increases, attributed to increase in Dean effects and turbulence intensity. Microbial inactivation studies conducted at 47.55 gph showed 0.91 {+/-} 0.15 and 2.14 {+/-} 0.19 log reduction/ pass for B. cereus endospores and T1UV phage. Linear inactivation trend was observed against number of passes which clearly demonstrates equivalent fluence delivery during each pass. Lipid peroxidation value and volatiles profile did not change significantly at UV fluence of 60 mJ/cm2. Lower EEO value signifies the higher electrical efficiency of the system.

microbiology↗

bioRxiv2021

Predicted UV-C Sensitivity of Human and Non-human Vertebrate (+) ssRNA Viruses

Epidemic and pandemic infectious diseases caused by RNA viruses constitute a significant hazard to human and animal health. Disinfection is an essential aspect of infection prevention and control measures. In this study, we estimated UV-C sensitivity of 83 human and veterinary pathogenic (+) ssRNA viruses by developed pyrimidine dinucleotide frequency-based genomic model. The data showed that the avian infectious bronchitis virus (genus: {gamma}-coronavirus) with an estimated D90 value of 17.8 J/m2 was highly UV sensitive, whereas Salivirus NG-J1 (genus: salivirus) with a D90 value of 346.4 J/m2 was highly UV resistant. Overall, the trend of UV-C sensitivity of (+) ssRNA virus families followed as Coronaviridae < Flaviviridae < Togadoviridae < Arteriviridae, Matonaviridae, Astroviridae < Caciviridae < Picornaviridae < Nodaviridae < Herpeviridae. The results revealed that the enveloped viral families (Coronaviridae, Flaviviridae, Togadoviridae Arteriviridae, and Matonaviridae) are more UV-C sensitive than other nonenveloped families. Further validation of the model estimated UV sensitivity with literature available experimental data showed good agreement of predicted values. The estimates presented here could make it possible to reasonably predict UV-C disinfection efficiency of human and veterinary pathogenic viruses, which need specific biosafety requirements and/or difficult to cultivate in lab conditions.

microbiology↗

bioRxiv2021

Evaluation of UV-A LED technology on the reduction of spiked aflatoxin B1 and aflatoxin M1 in whole milk: toxicity analysis using liver hepatocellular cells

The effectiveness of a UV-A light emitting diode system (LED) to reduce the concentrations of aflatoxin B1, aflatoxin M1 (AFB1, AFM1) in whole milk (WM) was investigated. Irradiation experiments were conducted using an LED system operating at 365 nm. Known concentrations of aflatoxins were spiked in WM and irradiated at quantified UV doses which was calculated based on the average volumetric intensity. LC-MS/MS product ion scans were used to identify and semi-quantify photodegraded products of AFB1 and AFM1. It was observed that UV irradiation significantly reduced aflatoxins in WM, p<0.05. In comparison to control, the maximum UV-A exposure reduced AFB1 and AFM1 concentrations to 78.2 {+/-} 2.36 % (at 836 mJ/cm2) and 65.7 {+/-} 1.65% (at 857 mJ/cm2), respectively. In cell culture studies, our results demonstrated that the increase of UV-A dosage decreased the aflatoxins-induced cytotoxicity in HepG2 cells, and no significant aflatoxin-induced cytotoxicity was observed at highest given UV-A irradiation of 777 (AFB1), 838 (AFM1), and 746 (total AFs) mJ/cm2. Sensory quality of product, cytotoxicity, and mutagenicity of UV exposed aflatoxins in WM using animal models is warranted in the future.

microbiology↗

bioRxiv2020

Phycobilins as potent food bioactive broad-spectrum inhibitor compounds against Mpro and PLpro of SARS-CoV-2 and other coronaviruses: A preliminary Study

In the twenty first century, we have witnessed three corona virus outbreaks; SARS in 2003, MERS in 2012 and ongoing pandemic COVID-19. To prevent outbreaks by novel mutant strains, we need broad-spectrum antiviral agents that are effective against wide array of coronaviruses. In this study, we scientifically investigated potent food bioactive broad-spectrum antiviral compounds by targeting Mpro and PLpro proteases of CoVs using in silico and in vitro approaches. The results revealed that phycocyanobilin (PCB) showed potential inhibitor activity against both proteases. PCB had best binding affinity to Mpro and PLpro with IC50 values of 71 m and 62 m, respectively. In addition, in silico studies of Mpro and PLpro enzymes of other human and animal CoVs indicated broad spectrum inhibitor activity of the PCB. Like PCB, other phycobilins such as phycourobilin (PUB), Phycoerythrobilin (PEB) and Phycoviolobilin (PVB) showed similar binding affinity to SARS-CoV-2 Mpro and PLpro

microbiology↗

bioRxiv2020

Genomic modeling as an approach to identify surrogates for use in experimental validation of SARS-CoV-2 and HuNoVs inactivation by UV-C treatment

Severe Acute Respiratory Syndrome coronavirus-2 (SARS-CoV-2) is responsible for the COVID-19 pandemic that continues to pose significant public health concerns. While research to deliver vaccines and antivirals are being pursued, various effective technologies to control its environmental spread are also being targeted. Ultraviolet light (UV-C) technologies are effective against a broad spectrum of microorganisms when used even on large surface areas. In this study, we developed a pyrimidine dinucleotide frequency based genomic model to predict the sensitivity of select enveloped and non-enveloped viruses to UV-C treatments in order to identify potential SARS-CoV-2 and human noroviruses surrogates. The results revealed that this model was best fitted using linear regression with r2=0.90. The predicted UV-C sensitivity (D90 - dose for 90% inactivation) for SARS-CoV-2 and MERS-CoV was found to be 21 and 28 J/m2, respectively (with an estimated 18 J/m2 as published for SARS-CoV-1), suggesting that coronaviruses are highly sensitive to UV-C light compared to other ssRNA viruses used in this modeling study. Murine hepatitis virus (MHV) A59 strain with a D90 of 21 J/m2 close to that of SARS-CoV-2 was identified as a suitable surrogate to validate SARS-CoV-2 inactivation by UV-C treatment. Furthermore, the non-enveloped human noroviruses (HuNoVs), had predicted D90 values of 69.1, 89 and 77.6 J/m2 for genogroups GI, GII and GIV, respectively. Murine norovirus (MNV-1) of GV with a D90 = 100 J/m2 was identified as a potential conservative surrogate for UV-C inactivation of these HuNoVs. This study provides useful insights for the identification of potential nonpathogenic surrogates to understand inactivation kinetics and their use in experimental validation of UV-C disinfection systems. This approach can be used to narrow the number of surrogates used in testing UV-C inactivation of other human and animal ssRNA viral pathogens for experimental validation that can save cost, labor and time.

microbiology↗