Search results for "ACID BACTERIA"

An investigation of the bacteriocinogenic potential of lactic acid bacteria associated with wheat (triticum durum) kernels and non-conventional flours

2008

One hundred and thirty-seven lactic acid bacteria (LAB), previously isolated from wheat (Triticum durum) grains and non-conventional flour samples, were tested for the production of antibacterial substances. A total of 16 strains (5 Enterococcus faecium, 5 Enterococcus mundtii, 4 Pediococcus pentosaceus, 1 Lactobacillus coryniformis and 1 Lactococcus garvieae) were found to inhibit the growth of Listeria innocua. The antibacterial activities were preliminarily investigated for their general behaviour with proteolytic (proteinase K, protease B and trypsin), amylolytic (α-amylase) and lipolytic (lipase) enzymes, after heat treatment, and exposure to different pHs and ethanol concentrations. B…

Anaerobic Reduction of Glycerol to Propanediol-1.3 by Lactobacillus brevis and Lactobacillus buchneri

1984

Summary Three strains of Lactobacillus brevis and one strain of Lactobacillus buchneri grew very poorly on glucose. Good growth was observed on glucose plus glycerol; while glucose was fermented to acetate or ethanol, lactate and CO 2 , glycerol was dehydrated to 3-hydroxypropanal and subsequently reduced to propanediol-1.3. Cell extracts of L. brevis and L. buchneri grown on glucose plus glycerol contained a B 12 -dependent glycerol dehydratase and a propanediol-1.3 dehydrogenase. Glycerol was not metabolized when used as the only substrate. Fructose as sole carbon source was partially reduced to mannitol. The joint fermentation of fructose and glycerol yielded propanediol-1.3 from glycero…

Effect of different salting technologies on the chemical and microbiological characteristics of PDO Pecorino Siciliano cheese

2011

The present work was carried out to evaluate the effect of two salting technologies [dry salting (DS) and the combined dry-brine salting (DBS)] on the chemicophysical and microbiological characteristics of PDO Pecorino Siciliano cheeses of different final weight (6 and 12 kg). Dry matter was significantly influenced by both salting process and final size. Twelve kilogram cheeses treated by DBS showed higher protein content with higher soluble nitrogen per cent than 6 kg cheeses. Salt content was in the range 3.1–4.0% on dry matter. The colour did not show significant differences for any of the factors, but 12 kg cheeses subjected to DS showed higher yellow index than the other cheeses. The …

Evaluation of curd cooking on microbiological characteristics of “Grana” type pressed cheeses processed from raw ewes’ milk

2018

This work was carried out to pursue a double objective: to improve the hygienic safety of cheeses produced from raw ewes’ milk; and to produce a new typology of cheese through the application of “Grana” technology. With this in mind, raw milk from an individual farm was transformed under controlled condition at a pilot dairy plant. The production technology included the partial skimming of the evening and morning milk mixture by cream surfacing, the addition of a natural whey starter cultures (NWSC) prepared with four selected Streptococcus thermophilus strains (PON6, PON244, PON261 e PON413) isolated from raw ewes’ cheese productions (Gaglio et al., 2014), milk clotting at 38°C, curd cooki…

Advanced Strategies for Food-Grade Protein Production: A New

2019

Food-grade production of recombinant proteins in Gram-positive bacteria, especially in LAB (i.e., Lactococcus, Lactobacillus, and Streptococcus), is of great interest in the areas of recombinant enzyme production, industrial food fermentation, gene and metabolic engineering, as well as antigen delivery for oral vaccination. Food-grade expression relies on hosts generally considered as safe organisms and on clone selection not dependent on antibiotic markers, which limit the overall DNA manipulation workflow, as it can be carried out only in the expression host and not in E. coli. Moreover, many commercial expression vectors lack useful elements for protein purification. We constructed a “sh…

The influence of backslopping on lactic acid bacteria diversity in tarhana fermentation

2020

Tarhana is produced at batch systems in which the microbiota has changed accordingly to the microbial load from ingredients. In order to stabilize the microbiota, the effects of backslopping carried out under different temperature regimes (25 and 30 °C), pH (3.70 and 4.00) and inoculation rates (5, 10 and 15%) on lactic acid bacteria (LAB) diversity were determined in tarhana dough. LAB and Total Aerobic Mesophilic Bacteria (TAMB) numbers increased in all tarhana dough samples subjected to backslopping. Temperature and pH significantly affected the microbiological diversity of tarhana whereas the different inoculation rates did not. Tarhana dough showed complex tarhana microbiota following …

Innovative and Applied Research in Biology: Proceedings, Vol. 3/2021

2021

The collection contains SCIENTIFIC articles on the topics of the LU 79 conference reports. The main focus is on innovative and applied research in biology and interdisciplinary fields.

Removal of Cu(II) and Pb(II) from aqueous solutions by lacit acid bacteria

2015

Celem pracy było porównanie zdolności usuwania Cu(II) i Pb(II) z roztworu wodnego przez bakterie kwasu mlekowego (LAB). Badano wpływ różnych parametrów, tj. stężenia jonów metali, pH i czas kontaktu, na proces usuwania jonów miedzi i ołowiu. Do opisu izoterm adsorpcji jonów metali przez biomasę LAB zastosowano modele Langmuira i Freundlicha. Uzyskane dane doświadczalne były lepiej dopasowane do modelu Langmuira niż Freundlicha. Sorbent wykazał maksymalną zdolność sorpcyjną, wynoszącą 11,07 i 10.51 mg · g–1 odpowiednio dla jonów Cu(II) i Pb(II). Optymalne warunki biosorpcji obu jonów metali wynosiły: pH 6,0 i czas równowagi 40 minut. Omówiono również udział grup funkcyjnych na powierzchni bi…

APPLICATION OF SELECTED LACTIC ACID BACTERIA FOR THE YEAR-ROUND PRODUCTION OF VASTEDDALIKE CHEESE

2014

I batteri lattici delle cariossidi del grano: influenza geografica, varietale e del periodo di invecchiamento

2021

Il presente articolo riporta i dati di alcune ricerche volte a risalire all’origine dei batteri lattici degli impasti acidi. A tal proposito, i batteri lattici del frumento di quattro varietà moderne sono stati monitorati a partire dalle spighe. Le cariossidi ospitavano livelli di microrganismi inferiori rispetto a quelli rilevati sulle spighe e queste ultime livelli inferiori rispetto alle semole. La minore biodiversità lattica è stata riscontrata sulle cariossidi, mentre le semole hanno mostrato la maggiore ricchezza di specie e ceppi. Al fine di valutare la resistenza dei batteri lattici del grano durante l’invecchiamento, le cariossidi di due varietà antiche e due moderne di grani duri …