scholarly journals Molecular identification and technological properties of yeasts isolated from spontaneously fermented cassava waste pulp

2021 ◽  
Vol 20 (2) ◽  
pp. e898
Author(s):  
Adelodun L. Kolapo ◽  
Raoofat O. Salami ◽  
Gbemisola O. Onipede
Keyword(s):  
Bile Salt ◽  
Molecular Identification ◽  
Starter Culture ◽  
Its Region ◽  
Viable Count ◽  
Haemolytic Activity ◽  
Good Growth ◽  
Technological Properties ◽  
Specific Tolerance ◽  
Cassava Waste

The aim of this work was to report on molecular identification and technological properties of the yeast flora isolated from spontaneously fermented cassava waste pulp. This was done with a view of obtaining yeast strains that could be used as a starter culture for the fermentation of cassava waste pulp. Molecular identification was based on the nucleotide sequence of the ITS region of the genomic DNA of the yeast isolates while the technological properties evaluated include linamarase (U/mL), gelatinase, and haemolytic activity; growth at pH 2.5 and tolerance to 2 % bile salt. All the representative five isolated yeasts were identified as Geotrichum silvicola KLP04 – KLP08. The isolates exhibited linamarase activity ranging between 3.3 and 4.2 with strain KLP04 having the highest value and strain KLP05 the least. None of the isolates demonstrated gelatinase and haemolytic activity except strain KLP08 which was partially haemolytic. All the examined yeasts exhibited good growth at pH 2.5, with strain KLP08 having the highest viable counts of 4.1 log10cfu/ml and strain KLP04 the least value of 3.5 log10cfu/ml after 72 h of growth. All the identified yeasts showed strain-specific tolerance to 2% bile salt with strain KLP04 having the highest viable count of 4.3 log10cfu/ml and strain KLP08 the least value of 2.2 log10cfu/ml at the end of 72 h of incubation. Based on all the examined technological properties, Candida silvicola KLP04 strain had the highest potential to be considered for starter culture for the fermentation of cassava waste pulp.

Effects of Fermentative Factors on Biochemical, Microbiological and Sensory Characteristics of Probiotic Iranian Fermented Milk (Doogh)

2019 ◽  
Vol 15 (1) ◽  
pp. 40-47
Author(s):  
Elaheh Ahmadi ◽  
Reza Mohammadi ◽  
Sara Hasanvand ◽  
Milad Rouhi ◽  
Amir Mohammad Mortazavian ◽  
...  
Keyword(s):  
Incubation Temperature ◽  
Storage Temperature ◽  
Starter Culture ◽  
Fermented Milk ◽  
Biochemical Properties ◽  
Viable Count ◽  
Sensory Characteristics ◽  
Refrigerated Storage ◽  
Increase Rate ◽  
Probiotic Strains

Background: Doogh is a traditional Iranian fermented milk drink that is currently a very popular product in Iran. In the present study, the combined effects of incubation temperature, type of starter culture, and final pH of fermentation on the viability of two probiotic strains (Lactobacillus acidophilus La-5 (A) and Bifidobacterium lactis Bb-12 (B)) and biochemical and sensory characteristics of probiotic Doogh were investigated. </P><P> Method: Different treatments were prepared with yoghurt starter culture containing probiotics, using reconstituted skimmed milk with 6% of solid nonfat. They were incubated at 38°C or 44°C until pH 4.0 or pH 4.5 and were kept for 21 days at 4&#176;C or 8&#176;C storage temperature. The biochemical properties of treatments were evaluated during fermentation and refrigerated storage. The viable count and sensory attributes of treatments were studied at the end of fermentation and at the end of storage. </P><P> Results: Results showed that the greatest mean pH drop rate, mean acidity increase rate and mean redox potential increase rate and the shortest incubation time were observed in treatments incubated at 44&#176;C with final pH of 4.5. The highest survival of both probiotic strains during storage was related to treatments with fermentation temperature of 38&#176;C and final pH of 4.5. Treatments ABY1-38&#176;C-4.0 had the highest sensorial total acceptance at the end of refrigerated storage. </P><P> Conclusion: It would be concluded that the best treatment was ABY3-38&#176;C-4 stored at 8°C in regards of probiotics’ viability and sensory characteristics of Doogh. Thus, controlling the temperature of refrigerated storage is the most importance factor during storage and distribution.

Growth, nisA Gene Expression, and In Situ Activity of Novel Lactococcus lactis subsp. cremoris Costarter Culture in Commercial Hard Cheese Production

2017 ◽  
Vol 80 (12) ◽  
pp. 2137-2146 ◽  
Author(s):  
Dimitrios Noutsopoulos ◽  
Athanasia Kakouri ◽  
Eleftheria Kartezini ◽  
Dimitrios Pappas ◽  
Efstathios Hatziloukas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lactococcus Lactis ◽  
Starter Culture ◽  
Fold Increase ◽  
Raw Milk ◽  
Good Growth ◽  
Lactococcus Lactis Subsp ◽  
Quantitative Expression ◽  
Hard Cheese

ABSTRACT This study evaluated in situ expression of the nisA gene by an indigenous, nisin A–producing (NisA+) Lactococcus lactis subsp. cremoris raw milk genotype, represented by strain M78, in traditional Greek Graviera cheeses under real factory-scale manufacturing and ripening conditions. Cheeses were produced with added a mixed thermophilic and mesophilic commercial starter culture (CSC) or with the CSC plus strain M78 (CSC+M78). Cheeses were sampled after curd cooking (day 0), fermentation of the unsalted molds for 24 h (day 1), brining (day 7), and ripening of the brined molds (14 to 15 kg each) for 30 days in a fully controlled industrial room (16.5°C; 91% relative humidity; day 37). Total RNA was directly extracted from the cheese samples, and the expression of nisA gene was evaluated by real-time reverse transcription PCR (qRT-PCR). Agar overlay and well diffusion bioassays were correspondingly used for in situ detection of the M78 NisA+ colonies in the cheese agar plates and antilisterial activity in whole-cheese slurry samples, respectively. Agar overlay assays showed good growth (&gt;8 log CFU/g of cheese) of the NisA+ strain M78 in coculture with the CSC and vice versa. The nisA expression was detected in CSC+M78 cheese samples only, with its expression levels being the highest (16-fold increase compared with those of the control gene) on day 1, followed by significant reduction on day 7 and almost negligible expression on day 37. Based on the results, certain intrinsic and mainly implicit hurdle factors appeared to reduce growth prevalence rates and decrease nisA gene expression, as well as the nisin A–mediated antilisterial activities of the NisA+ strain M78 postfermentation. To our knowledge, this is the first report on quantitative expression of the nisA gene in a Greek cooked hard cheese during commercial manufacturing and ripening conditions by using a novel, rarely isolated, indigenous NisA+ L. lactis subsp. cremoris genotype as costarter culture.

scholarly journals Molecular identification of poisonous mushrooms using nuclear ITS region and peptide toxins: a retrospective study on fatal cases in Thailand

2016 ◽  
Vol 41 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Sittiporn Parnmen ◽  
Sujitra Sikaphan ◽  
Siriwan Leudang ◽  
Thitiya Boonpratuang ◽  
Achariya Rangsiruji ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Molecular Identification ◽  
Its Region ◽  
Nuclear Its ◽  
Peptide Toxins ◽  
Poisonous Mushrooms

Characterization and Selection of LAB Isolated from Inner Mongolia Traditional Meat Sausages

2012 ◽  
Vol 554-556 ◽  
pp. 1400-1405
Author(s):  
Yan Duan ◽  
Wen Rui Guo ◽  
Lin Su ◽  
Yue Ying Guo ◽  
Ye Jin
Keyword(s):  
Biogenic Amine ◽  
Inner Mongolia ◽  
Acid Production ◽  
Starter Culture ◽  
Technological Properties ◽  
Lactobacillus Curvatus ◽  
Biochemical Tests ◽  
Gram Positive ◽  
Hydrolysis Of ◽  
Selection Of

A total of 69 gram-positive, catalase-negative strains isolated from Inner Mongolia traditional meat sausages were characterized in respect to their technological properties, including acid production, salt and nitrite tolerance, gas, slime and H2S production, hydrolysis of arginine and biogenic amine production. All of the isolated strains decrease the pH below 5.0 after 24h of cultivation. All isolates are able to grow with 6.5% NaCl or with 150mg L-1NaNO2and 51 isolates are able to grow with 10% NaCl. All isolates don’t produce gas and slime. 54 isolates don’t produce H2S. 23 isolated strains don’t produce NH3 from arginine, and 40 isolates don’t produce biogenic amine. Consolidation of these results, 8 strains show the best technological properties to be used as starter culture for sausage production. The bacterial selected are then subjected to biochemical tests using the API 50 CH and they are identified as 6 Lactobacillus planarum and 2 Lactobacillus curvatus.

scholarly journals WildTermitomycesSpecies Collected from Ondo and Ekiti States Are More Related to African Species as Revealed by ITS Region of rDNA

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Victor Olusegun Oyetayo
Keyword(s):  
Sequence Analysis ◽  
Phylogenetic Tree ◽  
Molecular Identification ◽  
Internal Transcribed Spacer ◽  
Its Region ◽  
Its Sequence ◽  
African Countries ◽  
African Species ◽  
Its Sequence Analysis ◽  
Degree Of Similarity

Molecular identification of eighteenTermitomycesspecies collected from two states, Ondo and Ekiti in Nigeria was carried out using the internal transcribed spacer (ITS) region. The amplicons obtained from rDNA ofTermitomycesspecies were compared with existing sequences in the NCBI GenBank. The results of the ITS sequence analysis discriminated between all theTermitomycesspecies (obtained from Ondo and Ekiti States) andTermitomycessp. sequences obtained from NCBI GenBank. The degree of similarity of T1 to T18 to gene ofTermitomycessp. obtained from NCBI ranges between 82 and 99 percent.Termitomycesspecies from Garbon with ascension number AF321374 was the closest relative of T1 to T18 except T12 that has T. eurhizus and T. striatus as the closet relative. Phylogenetic tree generated with ITS sequences obtained from NCBI GenBank data revealed that T1 to T18 are more related toTermitomycesspecies indigenous to African countries such as Senegal, Congo, and Gabon.

scholarly journals Morphological and molecular identification of phytophthora species from maple trees in Serbia

Genetika ◽  
2014 ◽  
Vol 46 (2) ◽  
pp. 353-368 ◽  
Author(s):  
Ivan Milenkovic ◽  
Justyna Nowakowska ◽  
Tomasz Oszako ◽  
Katarina Mladenovic ◽  
Aleksandar Lucic ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Genomic Dna ◽  
Its Region ◽  
Phytophthora Species ◽  
Morphological Identification ◽  
First Report ◽  
Phytophthora Spp ◽  
Isolated Species

The paper presents the results of the study performed with aims to determine the presence and diversity of Phytophthora species on maple trees in Serbia. Due to high aggressiveness and their multicyclic nature, presence of these pathogens is posing significant threat to forestry and biodiversity. In total, 29 samples of water, soil and tissues were taken from 10 different localities, and six different maple hosts were tested. After the isolation tests, 17 samples from five different maple hosts were positive for the presence of Phytophthora spp., and 31 isolates were obtained. After the detailed morphological and physiological classification, four distinct groups of isolates were separated. DNA was extracted from selected representative isolates and molecular identification with sequencing of ITS region was performed. Used ITS4 and ITS6 primers successfully amplified the genomic DNA of chosen isolates and morphological identification of obtained isolates was confirmed after the sequencing. Four different Phytophthora species were detected, including P. cactorum, P. gonapodyides, P. plurivora and P. lacustris. The most common isolated species was homothallic, and with very variable and semipapillate sporangia, P. plurivora with 22 obtained isolates. This is the first report of P. plurivora and P. gonapodyides on A. campestre, P. plurivora and P. lacustris on Acer heldreichii and first report of P. lacustris on A. pseudoplatanus and A. tataricum in Serbia.

Technological properties of beneficial bacteria from the dairy environment and development of a fermented milk with the beneficial strain Lactobacillus casei MRUV6

2020 ◽  
Vol 87 (2) ◽  
pp. 259-262
Author(s):  
Monique Colombo ◽  
Svetoslav D. Todorov ◽  
Antonio F. Carvalho ◽  
Luís A. Nero
Keyword(s):  
Lactobacillus Casei ◽  
Starter Culture ◽  
Fermented Milk ◽  
Dairy Production ◽  
Technological Properties ◽  
Beneficial Bacteria ◽  
Production Chain ◽  
Technological Potential ◽  
Environment And Development ◽  
Candidate Strain

AbstractIn this research paper we describe the technological properties of beneficial lactic acid bacteria (LAB) obtained from a dairy production chain and the development of a fermented milk produced with Lactobacillus casei MRUV6. Fifteen LAB isolates (Lactobacillus sp., Pediococcus sp. and Weissela sp.) presented acidifying abilities (pH ranges from 0.73 to 2.11), were able to produce diacetyl (except by 5 isolates) and exopolysaccharides, and two were proteolytic. L. casei MRUV6 was selected for producing a fermented milk, stored up to 35 d at 4 and 10°C. Counts on MRS agar with added vancomycin (10 mg/l) and MRS agar with added bile salts (1.5% w/v) ranged from 9.7 to 9.9 log CFU/g, independently of the tested conditions, indicating stability and intestinal resistance of L. casei MRUV6, despite some significant differences (P < 0.05). The study demonstrated the technological potential of a potential probiotic candidate strain, L. casei MRUV6, to be used as a starter culture in the dairy industry.

scholarly journals Genome Sequence of Lactobacillus brevis Strain D6, Isolated from Smoked Fresh Cheese

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Ravi Kant ◽  
Ksenija Uroić ◽  
Ulla Hynönen ◽  
Blaženka Kos ◽  
Jagoda Šušković ◽  
...  
Keyword(s):  
Intestinal Epithelial Cells ◽  
Starter Culture ◽  
Lactobacillus Brevis ◽  
Matrix Proteins ◽  
Intestinal Epithelial ◽  
Technological Properties ◽  
Fresh Cheese ◽  
Protein Strain ◽  
Immunomodulatory Potential ◽  
Cheese Production

The autochthonous Lactobacillus brevis strain D6, isolated from smoked fresh cheese, carries a 45-kDa S-layer protein. Strain D6 has shown adhesion to extracellular matrix proteins and to Caco-2 intestinal epithelial cells, as well as immunomodulatory potential and beneficial milk technological properties. Hence, it could be used as a potential probiotic starter culture for cheese production.

scholarly journals Ectomycorrhizae of Tomentella badia: description and molecular identification

2013 ◽  
Vol 48 (2) ◽  
pp. 155-171 ◽  
Author(s):  
Andrea Binder ◽  
Derek Peršoh ◽  
Nourou S. Yorou ◽  
Rita Verma ◽  
Claus Bässler ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Picea Abies ◽  
Molecular Identification ◽  
Its Region ◽  
Molecular Phylogenetic Analysis ◽  
Functional Characteristics ◽  
Molecular Phylogenetic ◽  
Dark Blue

Species within the genera <em>Tomentella </em>are among the most important ECM in forests. However, our knowledge about their functional characteristics is still rather limited. The ectomycorrhizae of <em>Tomentella badia </em>on <em>Picea abies </em>are described here in detail and compared to the non-identified ECM <em>Piceirhiza obscura</em>. A pseudoparenchymatous mantle formed by epidermoid cells is covered by heaps of epidermoid cells. This mantle type is regarded as a new one and designated as mantle type R. Many cells filled with dark blue contents and/or blue granules, together with clampless hyphae, are distinct characters of these ectomycorrhizae. Molecular-phylogenetic analysis of the ITS region was used for identification.

scholarly journals Profiling of Microbial Content and Growth in Fermented Maize Based Products from Western Kenya

2018 ◽  
Vol 6 (2) ◽  
pp. 509-519
Author(s):  
Herve Mwizerwa ◽  
George Ooko Abong ◽  
Samuel Kuria Mbugua ◽  
Michael Wandayi Okoth ◽  
Patrick Gacheru ◽  
...  
Keyword(s):  
Starter Culture ◽  
Titratable Acidity ◽  
Viable Count ◽  
Lactobacillus Fermentum ◽  
Probiotic Properties ◽  
Maize Flour ◽  
Fermentation Time ◽  
Western Kenya ◽  
Cereal Products ◽  
Molecular Tests

In most parts of Africa, the process of fermentation is not controlled and does not adhere to good manufacturing practices, therefore spoilage and pathogenic microorganisms can alter the quality of the end product and may cause foodborne illness.Traditional fermented products are mostly processed in an environment which creates a selection of microorganisms that produce the desired end product. In an attempt to find Lactobacilli which have probiotic properties and can be used in the development of starter culture for controlled fermentation of cereal products, the microbial populations of maize flour, overnight soaked dough, fermented cooked porridge, Mkarango and Busaawere enumerated and the inherent lactobacilli isolated. The microbial and biochemical profiles of the 6 days spontaneous Mkarangofermentation process were determined.The total viable count was 6.93 log cfu/g for fermented cooked porridge, 7.70 log cfu/g in Mkarango and 8.58 log cfu/g forBusaa. Lactobacillicounts were higher in maize flour with 7.43 log cfu/g whileEnterobactericeae were lower in Mkarango.The highest moulds and yeasts counts were observed forBusaa, 7.25 log cfu/g.The lactobacilli isolates from fermented maize based products from western Kenya were predominantly Lactobacillus fermentum andLactobacillus Plantarum.During fermentation time, Lactobacilliincreased from 6.62 to 12.46 log cfu/gafter 3 daysof fermentation. From day 4, an increase in moulds and yeast count was observed, varying from 8.42 to 10.53 log cfu/g. Enterobactericeae count decreased from 5.99 log cfu/g on day 1 to less than 1 log cfu/g on day 6.Titratable acidity increased from 0.32% to 0.73% on day 5. Inversely, the pH of Mkarangodecreased sharply from 6.64 to 3.64 on day 5 and slightly increased on the last day of fermentation. The microbial status of finished fermented maize based products is predominated by Lactobacilli and their isolates are predominantly Lactobacilli especially Lactobacillus fermentum andLactobacillus Plantarumthough further molecular tests are needed to confirm the species.

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