scholarly journals Comparison of Six Commercial Meat Starter Cultures for the Fermentation of Yellow Mealworm (Tenebrio molitor) Paste

2019 ◽  
Vol 7 (11) ◽  
pp. 540 ◽  
Author(s):  
Borremans An ◽  
Crauwels Sam ◽  
Vandeweyer Dries ◽  
Smets Ruben ◽  
Verreth Christel ◽  
...  
Keyword(s):  
Bacterial Community Composition ◽  
Amplicon Sequencing ◽  
Tenebrio Molitor ◽  
Fermented Food ◽  
Starter Cultures ◽  
Lactobacillus Curvatus ◽  
Clostridium Species ◽  
Pure Strain ◽  
Yellow Mealworm ◽  
Illumina Amplicon Sequencing

In this study, six commercial meat starters, each consisting of a pure strain of a lactic acid-fermenting bacterium (including Lactococcus lactis, Lactobacillus curvatus, L. farciminis, L. plantarum, L. sakei, and Pediococcus acidilactici), were tested for their ability to ferment a paste produced from the yellow mealworm (Tenebrio molitor). During fermentation, microbial counts, pH, and the bacterial community composition were determined. In addition, UPLC-MS was applied to monitor the consumption of glucose and the production of glutamic (Glu) and aspartic (Asp) acid. All tested starters were able to ferment the mealworm paste, judged by a pH reduction from 6.68 to 4.60–4.95 within 72 h. Illumina amplicon sequencing showed that all starters were able to colonize the substrate efficiently. Moreover, the introduction of the starter cultures led to the disappearance of Bacillus and Clostridium species, which were the dominant microorganisms in un-inoculated samples. Of the six cultures tested, Lactobacillus farciminis was most promising as its application resulted in the largest increase (±25 mg/100 g of paste) in the content of free glutamic and aspartic acid. These amino acids are responsible for the appreciated umami flavour in fermented food products and might stimulate the acceptance of insects and their consumption.

scholarly journals Metagenomic analysis of bacterial community composition in Dhanaan: Ethiopian traditional fermented camel milk

2019 ◽  
Vol 366 (Supplement_1) ◽  
pp. i127-i132
Author(s):  
Tesfemariam Berhe ◽  
Richard Ipsen ◽  
Eyassu Seifu ◽  
Mohamed Y Kurtu ◽  
Angelina Fugl ◽  
...  
Keyword(s):  
Bacterial Community Composition ◽  
Safety Evaluation ◽  
Operational Taxonomic Unit ◽  
Amplicon Sequencing ◽  
Starter Cultures ◽  
Camel Milk ◽  
Rrna Gene ◽  
Food Grade ◽  
Streptococcus Species ◽  
Metagenomic Approach

ABSTRACT This study was conducted to evaluate the safety and bacterial profile of Dhanaan (Ethiopian traditional fermented camel milk). The composition of the microbial community in Dhanaan samples was analysed by a metagenomic approach of 16S rRNA gene amplicon sequencing. Metagenomic profiling identified 87 different bacterial microorganisms (OTUs) in six samples analysed. Although the Dhanaan samples contained various lactic acid bacteria (LAB), they also all contained undesirable microorganisms in large proportions. The following LAB genera were identified: Streptococcus, Lactococcus and Weissella. One Streptococcus species represented by OTU-1 (operational taxonomic unit) was found in all Dhanaan samples and the dominating species in four out of six samples. This common isolate was found to be closely related to S. lutetiensis and S. infantarius. Undesirable microorganisms from genera such as Escherichia, Klebsiella, Enterobacter, Acinetobacter and Clostridium were, however, also frequent, or even dominant in Dhanaan samples. Thus, this calls for a change in the Dahnaan manufacturing practice to an improved and safer production system. Starter cultures suitable for Dhanaan production might be developed from the Streptococcus, Weissella and Lactococcus microorganisms identified in this study. However, further safety evaluation and technological characterization need to be conducted on strains defined by OTU-1, OTU-2, OTU-3, OTU-8 and OTU-35 before they can be used as food grade starter cultures.

Biosynthesis and Secretion of Serine Peptidase SerP38 from Tenebrio molitor in the Yeast Komagataella kurtzmanii

2020 ◽  
Vol 36 (6) ◽  
pp. 78-86
Author(s):  
P.I. Akentyev ◽  
I.I. Gubaidullin ◽  
N.I. Zhiganov ◽  
V.F. Tereshchenkova ◽  
E.N. Elpidina ◽  
...  
Keyword(s):  
Culture Medium ◽  
Polypeptide Chain ◽  
Tenebrio Molitor ◽  
Enzyme Secretion ◽  
Trypsin Treatment ◽  
Yellow Mealworm ◽  
Serine Peptidase

A strain of the Komagataella kurtzmanii yeast, a producer of recombinant peptidase SerP38 from the yellow mealworm Tenebrio molitor, has been obtained. The level of the pro-enzyme secretion was 20-50 mg/L. It was shown that, during secretion in yeast, the target His6-tagged protein was produced in two forms. One of them was a monomer that was efficiently purified by Ni-NTA chromatography and then activated with trypsin. Another form accumulated in the culture medium as oligomers prone to aggregation in the presence of Ni2+ ions and was not activated by trypsin treatment. Aggregation is likely the result of incorrect folding of the polypeptide chain. Tenebrio molitor, S1 family serine peptidase, SerP38, yeast, Komagataella kurtzmanii, ion-dependent aggregation

scholarly journals Graded Incorporation of Defatted Yellow Mealworm (Tenebrio molitor) in Rainbow Trout (Oncorhynchus mykiss) Diet Improves Growth Performance and Nutrient Retention

Animals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 187 ◽  
Author(s):  
Paulo Rema ◽  
Subramanian Saravanan ◽  
Benjamin Armenjon ◽  
Constant Motte ◽  
Jorge Dias
Keyword(s):  
Body Composition ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Growth Performance ◽  
Tenebrio Molitor ◽  
Nutrient Digestibility ◽  
Protein Meal ◽  
Yellow Mealworm ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss

Insects are emerging as a sustainable alternative to fishmeal and fish oil in aquafeeds. This study assessed the effect of graded incorporation levels of defatted yellow mealworm (Tenebrio molitor) protein meal on juvenile rainbow trout (Oncorhynchus mykiss) growth performance, body composition, and apparent nutrient digestibility. The trial comprised five dietary treatments: control diet with 25% fishmeal, and four experimental diets with yellow mealworm protein meal at 5%, 7.5%, 15%, or 25%, which corresponded to a fishmeal replacement of 20%, 30%, 60%, or 100%, respectively. After 90 days, the graded incorporation of insect protein meal led to a significant stepwise increase in final body weight, and a significant improvement of specific growth rate, feed conversion ratio, and protein efficiency ratio compared to the control treatment. Regardless of the incorporation level, the insect protein meal had no effects on fish whole-body composition and apparent digestibility coefficients of dry matter, protein, fat, phosphorus, and energy. Protein, phosphorus, and energy retention significantly increased in fish fed the diets with an insect protein meal. In conclusion, the yellow mealworm protein meal could effectively replace 100% of fishmeal in the diet of juvenile rainbow trout with positive effects on its overall zootechnical performance.

scholarly journals SARS-CoV-2 detection status associates with bacterial community composition in patients and the hospital environment

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Clarisse Marotz ◽  
Pedro Belda-Ferre ◽  
Farhana Ali ◽  
Promi Das ◽  
Shi Huang ◽  
...  
Keyword(s):  
Health Care Providers ◽  
Rna Virus ◽  
Bacterial Community Composition ◽  
Hospital Setting ◽  
Amplicon Sequencing ◽  
Hospital Environment ◽  
Rrna Gene ◽  
Sequence Variant ◽  
Care Providers ◽  
Single Amplicon

Abstract Background SARS-CoV-2 is an RNA virus responsible for the coronavirus disease 2019 (COVID-19) pandemic. Viruses exist in complex microbial environments, and recent studies have revealed both synergistic and antagonistic effects of specific bacterial taxa on viral prevalence and infectivity. We set out to test whether specific bacterial communities predict SARS-CoV-2 occurrence in a hospital setting. Methods We collected 972 samples from hospitalized patients with COVID-19, their health care providers, and hospital surfaces before, during, and after admission. We screened for SARS-CoV-2 using RT-qPCR, characterized microbial communities using 16S rRNA gene amplicon sequencing, and used these bacterial profiles to classify SARS-CoV-2 RNA detection with a random forest model. Results Sixteen percent of surfaces from COVID-19 patient rooms had detectable SARS-CoV-2 RNA, although infectivity was not assessed. The highest prevalence was in floor samples next to patient beds (39%) and directly outside their rooms (29%). Although bed rail samples more closely resembled the patient microbiome compared to floor samples, SARS-CoV-2 RNA was detected less often in bed rail samples (11%). SARS-CoV-2 positive samples had higher bacterial phylogenetic diversity in both human and surface samples and higher biomass in floor samples. 16S microbial community profiles enabled high classifier accuracy for SARS-CoV-2 status in not only nares, but also forehead, stool, and floor samples. Across these distinct microbial profiles, a single amplicon sequence variant from the genus Rothia strongly predicted SARS-CoV-2 presence across sample types, with greater prevalence in positive surface and human samples, even when compared to samples from patients in other intensive care units prior to the COVID-19 pandemic. Conclusions These results contextualize the vast diversity of microbial niches where SARS-CoV-2 RNA is detected and identify specific bacterial taxa that associate with the viral RNA prevalence both in the host and hospital environment.

scholarly journals Uncovering the Structure and Function of Microbial Communities Formed During Periodic Tilling of TNT and DNT Co-Contaminated Soils

2020 ◽  
Author(s):  
Saeed Keshani Langroodi ◽  
Yemin Lan ◽  
Ben Stenuit ◽  
Gail Rosen ◽  
Joseph B Hughes ◽  
...  
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
Contaminated Soils ◽  
Bacterial Community Composition ◽  
Amplicon Sequencing ◽  
Metagenomic Data ◽  
Military Conflict ◽  
Nitro Explosives ◽  
And Function ◽  
Aerobic And Anaerobic

Environmental contamination by 2,4,6-trinitrotoluene (TNT), historically the most widely used secondary explosive, is a long-standing problem in former military conflict areas and at manufacturing and decommissioning plants. In field test plots at a former explosives manufacturing site, removal of TNT and dinitrotoluenes (DNTs) was observed following periods of tillage. Since tilling of soils has previously been shown to alter the microbial community, this study was aimed at understanding how the microbial community is altered in soils with historical contamination of nitro explosives from the former Barksdale TNT plant. Samples of untilled pristine soils, untilled TNT-contaminated soils and tilled TNT-contaminated soils were subjected to targeted amplicon sequencing of 16S ribosomal RNA genes in order to compare the structure of their bacterial communities. In addition, metagenomic data generated from the TNT tilled soil was used to understand the potential functions of the bacterial community relevant to nitroaromatic degradation. While the biodiversity dropped and the Burkholderiales order became dominant in both tilled and untilled soil regardless of tillage, the bacterial community composition at finer taxonomic levels revealed a greater difference between the two treatments. Functional analysis of metagenome assembled genome (MAG) bins through systematic review of commonly proposed DNT and TNT biotransformation pathways suggested that both aerobic and anaerobic degradation pathways were present. A proposed pathway that considers both aerobic and anaerobic steps in the degradation of TNT in the scenario of the tilled contaminated soils is presented.

Effects of vacuum and multiflash drying on the microbiota and colour of dried yellow mealworm (Tenebrio molitor)

2021 ◽  
pp. 1-12
Author(s):  
R.E.Y. Seho ◽  
R.L. Monteiro ◽  
J. De Dea Lindner ◽  
M. Miotto ◽  
B.A.M. Carciofi ◽  
...  
Keyword(s):  
Water Activity ◽  
Challenge Test ◽  
High Water ◽  
Tenebrio Molitor ◽  
Microbial Reduction ◽  
Microbial Load ◽  
Vacuum Drying ◽  
Drying Time ◽  
Yellow Mealworm ◽  
Food And Feed

Larvae of Tenebrio molitor (yellow mealworm; YM) are an alternative to conventional animal protein as food and feed thanks to their high nutritional value and low environmental impact for production. Since some studies have reported high water activity (aw) with different microbial contamination levels, blanching and drying can be employed to reduce microbial load, enzymatic activity, moisture content, and water activity, ensuring safety and preserving YM for longer periods. This study applied rinsing or blanching followed by vacuum- or multiflash drying, aiming to preserve YM by reducing aw and the microbial load, enabling its use as food and feed. The processing impact on YM colour was evaluated, and they were also subjected to an Escherichia coli contaminated wheat bran to perform a challenge test to evaluate the effectiveness of the decontamination. Drying curves were determined for each situation. Multiflash drying procedure was faster than vacuum drying for reducing YM moisture. Additionally, blanched samples required a shorter period to reach the targeted water activity (0.2-0.3) than rinsed samples. Blanching plus vacuum drying reduced more than 5 log E. coli load in YM in the challenge test. Vacuum drying preserved YM brightness the most. In conclusion, this study showed that drying could provide shelf-stable YM. Besides, only 15 s of blanching before drying gives better brightness and leads to a greater microbial reduction after a relatively short drying time.

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