Sucrose Fermentation Research Articles

Metabolomics profiling of fermented cantaloupe juice and the potential application to extend the shelf life of fresh cantaloupe juice for six months at 8 °C

The aim of this study was to evaluate the potential of adding fermented cantaloupe juice at different concentrations to extend the shelf life of fresh cantaloupe juice stored at 8 °C for six months. Cantaloupe juice was fermented with Lactobacillus plantarum FBS05 for 48 h at 37 °C. The antimicrobial activity of the fermented juice was determined using microtiter plate assays, and the bioactive metabolites were identified using 1H NMR metabolomics analysis. Fermented juice was added to fresh juice at different ratios including 10:90, 20:80 and 30:70 (v/v) to determine the effects on the shelf life and sensory properties. Fermented cantaloupe juice demonstrated strong antibacterial activity against Escherichia coli, Salmonella typhimurium, Aspergillus flavus and Penicillium spp. The 1H NMR metabolomics profiling identified 23 metabolites in fermented and non-fermented cantaloupe juice. The PCA model demonstrated significant discrimination level between the fermented and non-fermented cantaloupe juice. The metabolites responsible for the discrimination were lactic acid, GABA, acetoin, acetoacetate, cellobiose and alanine in the fermented cantaloupe juice, and sucrose, glucose, mannose and epicatechin in non-fermented cantaloupe juice. The ratio 20:80 of fermented cantaloupe juice to the fresh juice extended the shelf life for 6 months at 8 °C and sustained good sensory properties for cantaloupe juice. The findings of this study showed high potential for the fermented cantaloupe juice to be added to the fresh cantaloupe juice as natural preservative to extend the shelf life and improve the sensory properties.

Characteristics of Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin Sensitive Staphylococcus aureus (MSSA) and their inhibitory response by ethanol extract of Abrus precatorius

Abstract. Mutmainnah BQ, Baktir A, Ni’matuzahroh. 2020. Characteristics of Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin Sensitive Staphylococcus aureus (MSSA) and their inhibitory response by ethanol extract of Abrus precatorius. Biodiversitas 21: 4076-4085. Three isolates of Staphylococcus bacteria with the code MRSA 22372, MSSA 22187 and MSSA 22366 originated from the urine of the patient at Dr. Regional General Hospital Soetomo, Clinical Microbiology Installation Surabaya, Indonesia. Differences in bacterial strains affect their sensitivity to antimicrobial agents. The active ingredient of the ethanol extract of the leaves of Abrus precatorius L. has the potential to inhibit bacterial growth. This study aims to further characterize the bacteria MRSA 22372, MSSA 22187 and MSSA 22366 based on morphological, biochemical and molecular characters and to compare the growth inhibitory response of these three bacteria due to the treatment of variations in the ethanol extract of A. precatorius of 25 mgL-1- 800 mgL-1 leaves. The results showed there were differences in the diameter of bacterial colonies, the ability to ferment glucose and sucrose, and the production of urease and catalase. The molecular characteristics of the three bacteria have no similarity in the order of nucleotide bases or phylogenetic proximity to each other. Ethanol extract of A. precatorius leaves at a concentration of 800 mgL-1 inhibited the growth of MSSA 22187 with an inhibition zone of 41 mm and decreased the MSSA 22366 growth by 67.6%. MIC value of ethanol extract of A. precatorius leaves in all three bacteria was 25 mgL-1 with growth inhibition up to 29.4%, 35.3%, and 29.4% respectively.
 Keyword : MRSA, MSSA, ethanol extract, Abrus precatorius L.

Isolation, identification and characterization of Staphylococcus sp. from Indian ethnic fermented fish product.

Staphylococci from Sheedal of Northeast India was isolated, identified and characterized. All the isolated staphylococci were found to be coagulase negative. Based on the rpoB gene sequences followed by analysis using NCBI-BLAST software, seven species of Staphylococcus namely, S. piscifermentans, S. condimenti, S. arlettae, S. sciuri, S. warneri, S. nepalensis and S. hominis were recognized. Phylogenetic analyses revealed three major cluster groups. All the seven Staphylococcus showed their NaCl tolerance from 2 to 8%. No species was able to grow at 55°C. Except S. arlettae and S. sciuri, all the isolated staphylococcal species exhibited growth at pH 4-8. No isolated species was able to ferment mannitol, sucrose and arabinose. All the species exhibited moderate to maximum proteolytic and lipolytic activities. All the seven species were found to be sensitive to the antibiotics, namely, erythromycin, norfloxacin, ampicillin, streptomycin and vancomycin, whereas all were resistant to co-trimoxazole. Only S. piscifermentans was found antagonist to Salmonella enterica, Escherichia coli and Bacillus subtilis, although the clear zone was minimal. All the staphylococcal species except S. arlettae and S. sciuri exhibited hydrophobicity ranging from 25 to 66%. The observed characteristics of isolated Staphylococci from Sheedal revealed their role in fish fermentation.

Screening of Yeast Cells for the Production of Wine from Banana and Pineapple Substrates

Wine, an alcoholic beverage is usually produced from juice of variety of fruits by the fermentative action of microorganisms particularly by yeasts. Several substrates such as pineapple, banana, watermelon, pawpaw and other fruits have been used to produce wine using Saccharomyces species. This study was undertaken using non- Saccharomyces to produce table wine with pineapple and banana fruits as substrates. Standard microbiological procedures were employed for yeasts cell isolation, sugar (sucrose) fermentation test, pH, ethanol, sucrose and glucose tolerance test were carried out respectively. Alcohol production by the yeasts was screened and the isolates were identified by genomic techniques. Twenty-two (22) yeasts isolated from palm wine (YW), banana (YB) and pineapple (YP) were screened for their ability to ferment sugar and fourteen (14) of the yeast isolates were positive while eight (8) were negative. The fourteen (14) isolates were further screened for their ability to tolerate pH, ethanol, sucrose and glucose. Tolerance tests for these fourteen (14) yeast isolates recorded values between a range of 3.0-5.0, 0-10% v/v, 5-20% w/v and 5-25% w/v for pH, ethanol, sucrose and glucose concentrations respectively. Statistically, there was a significant difference in the interaction effect for pH, ethanol, sucrose and glucose tolerance (OD600 nm) for yeast isolates at p value ≤ 0.0001. Five (5) yeast isolates had high tolerance ability to pH, ethanol, sucrose and glucose and were further screened for their ability to produce alcohol. The five (5) yeast isolates were identified as Meyerozyma guilliermondii strain 1621, Pichia guilliermondii strain PX-PAT, Meyerozyma caribbica strain Kw 1S7Y2, Meyerozyma caribbica strain Y-27400, Kodamaea ohmeri strain ww1-1 and they produced alcohol content of 7.6%, 6.5%, 2.9%, 2.5% and 0.3% respectively. Meyerozyma guilliermondii strain 1621 and Pichia guilliermondii strain PX-PAT 18 S isolated from palm wine exhibited good characteristics and produced high quantity of alcohol and are suitable for alcohol fermentation of substrates for wine production.

Selection of flooding stress tolerant sweetpotato cultivars based on biochemical and phenotypic characterization

Sweetpotato [Ipomoea batatas (L.) Lam] serves as a sustainable food source and ensures nutrition security in the face of climate change. Recently, farmers have developed increased interest in replacing rice with sweetpotato in paddy fields for higher income. However, sweetpotato is more susceptible to flooding stress than other abiotic stresses including drought and salinity. Here, we selected flooding tolerant sweetpotato cultivars based on biochemical characterization. Young seedlings of 33 sweetpotato cultivars were subjected to flooding stress for 20 days, and Yeonjami (YJM) was identified as the most flooding tolerant sweetpotato cultivar. Plant growth and biochemical characteristics of YJM were compared with those of Jeonmi (JM), a flooding sensitive sweetpotato cultivar. Under flooding stress, YJM showed higher content of chlorophyll and lower inhibition of plant height and fibrous root length than JM. Biochemical characterization revealed that although malondialdehyde and hydrogen peroxide contents were increased in fibrous roots of both cultivars, the amount of increase was 4-fold lower in YJM than in JM. Additionally, leaves of YJM showed higher ascorbate peroxidase activity than those of JM under flooding stress. Our results suggest that high membrane stability and antioxidant capacity are important flooding tolerance factors in sweetpotato. Furthermore, several flooding tolerance-related genes involved in starch and sucrose metabolism, fermentation, and cell wall loosening showed earlier induction and higher transcript levels in YJM leaves and fibrous roots than in JM tissues under flooding stress. Thus, phenotypic and biochemical characterization suggests that YJM could be used as a flooding tolerant sweetpotato cultivar.

Characterization of Thermophilic Microorganisms in the Geothermal Water Flow of El Chichón Volcano Crater Lake

This study reports for the first time the isolation, identification and characterization of lipase-producing thermophilic strain from the geothermal water of the El Chichón volcano crater lake. Two strains were identified by 16S rRNA sequencing as Geobacillus jurassicus CHI2 and Geobacillus stearothermophilus CHI1. Results showed that G. jurassicus CHI2 is Gram-positive, able to ferment maltose, fructose and sucrose and to hydrolyze starch and casein; while G. stearothermophilus CHI1 showed to be Gram-variable, able to ferment maltose and fructose and to hydrolyze starch. Colonies of both strains presented irregular shape, umbilicated elevation of gummy texture and cells presented flagellar movement to survive in fluids with high temperature and mass gradients due to complex phenomena of heat and mass transfer present in the geothermal fluids. Lipase production for G. stearothermophilus CHI1 was also evaluated. It was found that this strain possesses a growth associated with extracellular lipase production with a high activity of 143 U/mL at 8.3 h of incubation time, superior to the activities reported for other microorganisms of genus Geobacillus; for this reason, it can be said that the thermal flow of the El Chichón volcano crater lake can be a useful source of lipase-producing thermophilic bacteria.

Study on growth characteristics of Candida auris under different conditions in vitro and its in vivo toxicity

To investigate the characteristics of growth and metabolism and the in vivo toxicity of Candida auris under different conditions. We observed the growth of Candida auris and Candida albicans under routine culture conditions and in different pH and salt concentrations, and compared their activities of sugar fermentation using microbiochemical reaction tubes. Four-week-old nude mice were randomized into Candida auris infection group (n=5), Candida albicans infection group (n=5) and control group (n=5) for intragastric administration of 0.3 mL suspension the two Candida species (5×109 cfu/mL) or 0.3 mL normal saline. Samples of the liver, kidney, intestine, feces and blood were taken for analysis of the in vivo distribution and toxicity of Candida albicans by fungal culture and histopathological examination. Candida auris exhibited logarithmic growth at 8-24 h after inoculation and showed stable growth after 24 h. Candida auris showed optimal growth within the pH value range of 5-7 with a growth pattern identical to that of Candida albicans. Candida auris grew better than Candida albicans in media containing 5% and 10% NaCl, and could ferment glucose, sucrose, trehalose and sorbitol. Candida auris could be isolated from the feces, blood, liver and kidney of infected nude mice, and the liver had the highest fungal load (5.7 log10 cfu/g). Candida auris could cause pathological changes in the liver and intestine of the mice, but with a lesser severity as compared with Candida albicans. Candida auris exhibits optimal growth in mildly acidic or neutral conditions with a high salt tolerance, and can potentially penetrate the intestinal barrier into blood and lead to tissue injuries in hosts with immunosuppression.

Mrakia stelviica sp. nov. and Mrakia montana sp. nov., two novel basidiomycetous yeast species isolated from cold environments.

Five yeast strains were isolated from soil and sediments collected from Alps and Apennines glaciers during sampling campaigns carried out in summer 2007 and 2017, respectively. Based on morphological and physiological tests and on phylogenetic analyses reconstructed with ITS and D1/D2 sequences, the five strains were considered to belong to two related but hitherto unknown species within the genus Mrakia, in an intermediate position between Mrakia cryoconiti and Mrakia arctica. The names Mrakia stelviica (holotype DBVPG 10734T) and Mrakia montana (holotype DBVPG 10736T) are proposed for the two novel species and a detailed description of their morphological, physiological and phylogenetic features are presented. Both species fermented glucose, sucrose and trehalose, which is an uncommon feature in basidiomycetous yeasts, and showed septate hyphae with teliospore formation.

Staphylococcus ursi sp. nov., a new member of the 'Staphylococcus intermedius group' isolated from healthy black bears.

Six Staphylococcus strains were isolated from healthy black bears (Ursus americanus) in the Great Smoky Mountains National Park, Tennessee, USA. Phylogenetic analysis based on complete genome, 16S rRNA, dnaJ, hsp60, rpoB and sodA genes, and MALDI-TOF-MS main spectral profiles revealed that the strains belonged to one species and showed the closest relatedness to members of the ‘ Staphylococcus intermedius group’ (SIG), which include Staphylococcus intermedius , Staphylococcus pseudintermedius, Staphylococcus delphini and Staphyloccoccus cornubiensis. The strains were positive in SIG-specific and negative in individual species-specific PCR assays for the nuc gene. The strains can be differentiated from the other SIG species by the absence of sucrose fermentation, from S. intermedius DSM 20373T, S. pseudintermedius CCUG 49543T and S. cornubiensis DSM 105366T by the absence of methyl β-d-glucopyranoside fermentation and from S. delphini DSM 20771T by fermentation of trehalose. DNA relatedness of the type strain MI 10-1553T with the type strains of S. delphini , S. pseudintermedius , S. intermedius and S. cornubiensis was ≤48.2 % by digital DNA–DNA hybridization and ≤92.3 % by average nucleotide identity calculations. Iso-C15:0, anteiso-C15 : 0 and anteiso-C17 : 0 were the most common fatty acids. Polar lipids consisted of phosphadidylglycerols, phospholipids, glycolipid, diphosphatidylglycerol and aminophospholipid. Cell-wall peptidoglycan was of type A3α l-Lys-Gly3 (Ser; similar to A11.2 and A11.3). The respiratory quinone belonged to menaquinone 7 (MK-7). The G+C content of MI 10-1553T was 39.3 mol%. The isolated strains represent a novel species of the genus Staphylococcus , for which we propose the name Staphylococcus ursi sp. nov. The type strain is MI 10-1553T (=ATCC TSD-55T=CCOS 1900T).

Isolation and identification of two Serratia marcescens strains from silkworm, Bombyx mori.

Bacterial septicemia commonly occurs and usually cause huge losses in sericulture industry. Here, two pathogenic bacterial strains were isolated from dead silkworm and named as ZJ-1 and ZJ-2. Phenotypic and genotypic analysis results revealed that both of these two strains are closely related to Serratia marcescens (S. marcescens). The morphological as well as physiological and biochemical characteristics of ZJ-1 were accordant with S. marcescens mentioned in Bergey's manual of determinative bacteriology, whereas ZJ-2 showed some discrepancies such as the utilization of malonate and starch, fermentation of maltose and sucrose, and tests of urease, etc. Surprisingly, ZJ-2 could produce red pigment at high temperature (37°) but ZJ-1 could not. Besides, by analyzing the lethal concentration 50 (LC50) of ZJ-1 and ZJ-2, it was found that the virulence of ZJ-2 was lower than that of ZJ-1. These results revealed that ZJ-1 and ZJ-2 were two different strains of S. marcescens and that ZJ-2 was expected to be a safe (low-toxicity) and efficient strain for the production of red pigment. Nonetheless, further research in molecular level is needed to understand the regulation mechanism of pigment production and infection of ZJ-2.

Comprehensive depiction of novel heavy metal tolerant and EPS producing bioluminescent Vibrio alginolyticus PBR1 and V. rotiferianus PBL1 confined from marine organisms

The current study depicts the isolation of luminescent bacteria from fish and squid samples that were collected from Veraval fish harbour. From Indian mackerel, total 14 and from squid, total 23 bioluminescent bacteria were isolated using luminescence agar medium. Two bioluminescent bacteria with highest relative luminescence intensity PBR1 and PBL1 were selected. These two isolates were subjected to detailed biochemical characterization and were tested positive for 5 out of 13 biochemical tests. Furthermore, both PBR1 and PBL1 were able to ferment cellobiose, dextrose, fructose, galactose, maltose, mannose, sucrose and trehalose with acid production. Based on 16S rRNA partial gene sequence analysis, PBR1 was identified as Vibrio alginolyticus and PBL1 as V. rotiferianus. Antibiotic susceptibility test using paper-disc method showed that PBR1 and PBL1 were sensitive to chloramphenicol, ciprofloxacin, co-trimoxazole, gatifloxacin, levofloxacin, linezolid ad roxithromycin out of 18 antibiotics tested. Moreover, both strains were evaluated for their exopolysachharide (EPS) producing ability where PBR1 and PBL1 were able to yield 1.34 g% (w/v) and 2.45 g% (w/v) EPS respectively from 5 g% (v/v) sucrose concentration. Heavy metal toxicity assessment was carried out using agar well diffusion method with eight heavy metals and both the strains were sensitive to As(III), Cd(II), Ce(II), Cr(III), Cu(II), Hg(II) and while they showed resistance to Pb(II) and Sr(II). Based on these results, a study was conducted to demonstrate bio-removal of Pb and Sr by EPS of PBR1 and PBL1. Fourier transform infrared (FTIR) spectra revealed the functional groups of EPS involved in interaction with the heavy metals. Owing to the sensitivity for the remaining heavy metals, these bioluminescent bacteria can be used further for the development of luminescence-based biosensor.

Rhodospirillum centenum, A New Growth Stimulant and Antagonistic Bacteria Against Leaf Spot of Rice Caused by Curvularia lunata

The research objectives were to find Rhodospirillum spp. to promote plant growth and as antagonists to control leaf spot of rice. The results showed that rice var. RD41 and Pitsanulok 2 (PL2) had leaf spot caused by Curvularia lunata. R. centenum is gram negative, mobile cell motility and negative of gelatin activity test. SM41 and 61 showed glucose and lactose and/or sucrose fermentation activity, but SM72 and 92 were non-fermented activity. Isolates of R. centenum were antagonized C. lunata, a leaf spot pathogen. R. centenum expressed for ability to produce amylase, protease and lipase. R. centenum isolates SM41, SM61, SM72, and SM92 with C. lunata causing leaf spot and seed-borne fungus. In addition, the inoculated seeds var. RD 41 and Pitsanulok 2 (PL2) applied R. centenum 41, 61, 72 and 79 gave significantly better seed germination, shoot and root length. Isolate SM41 reduced disease incidence in rice var. RD41 which the disease index was on level 2 when the inoculated one was level 5. Isolate SM61 showed the disease index of level 2 but the inoculated control was level 5. It is the first report that R. centenum plays the role for growth stimulant and biological control agents against leaf spot of rice caused by C. lunata.

TEST THE ABILITY OF SEDIMENT BACTERIA ISOLATES IN DEGRADATING PHENOL

Phenol degrading bacteria can be found in various habitats in marine environments. This study aims to obtain bacteria from sediments that are able to degrade phenol. The process of bacterial purification and degradation was carried out from August to September 2018 at the Marine Microbiology Laboratory, Department of Marine Sciences, Faculty of Fisheries and Marine, University of Riau. Analysis of the reduction in phenol concentration was carried out using the APHA 5530 method using UV-VIS spectrophotometry conducted at the Health and Environment Laboratory. The bacterial isolates used as test bacteria were isolates BF1A, BF4B and BF9C. Bacterial and biochemical tests were carried out for all bacterial isolates. Two isolated showed mehyl red negative, all isolates were motile. Three isolates were positive catalase, able to ferment glucose and sucrose fermented citrate and two isolat were Gram negative bacterial. The three bacterial isolates were able to degrade phenol with the highest degradation for 1ppm shown in isolates BF1A, the highest degradation of concentrations of 2 ppm and 3 ppm was shown in isolates BF9C. Thus, the isolat BF9C was able to degrade the highest phenol.

A Convenient Fluorescence-Based Assay for the Detection of Sucrose Transport and the Introduction of a Sucrose Transporter from Potato into Clostridium Strains.

A convenient and effective sucrose transport assay for Clostridium strains is needed. Traditional methods, such as 14C-sucrose isotope labelling, use radioactive materials and are not convenient for many laboratories. Here, a sucrose transporter from potato was introduced into Clostridium, and a fluorescence assay based on esculin was used for the analysis of sucrose transport in Clostridium strains. This showed that the heterologously expressed potato sucrose transporter is functional in Clostridium. Recombinant engineering of high-level sucrose transport would aid sucrose fermentation in Clostridium strains. The assay described herein provides an important technological platform for studying sucrose transporter function following heterologous expression in Clostridium.

Molecular characterization of Pasteurella multocida pfhaB1 gene fragment from buffalo and cattle isolates from Nusa Tenggara Timur Indonesia

Almost all regions in Nusa Tenggara Timur East Nusa Tenggara (NTT) Province Indonesia are endemic areas of Haemorragic Septicaemia (HS), which is caused by Pasteurella multocida (P. multocida ) Serotypes B: 2. The fragment pfhaB1gene is one of the virulence factors of P. multocida.The objective of this study was to determaine the phylogenetic, homology of P. multocidapfhaB1gene fragment of isolatedfrom Buffalo and Cattle in NTT. The P. multocida isolateswere re-cultured and further microscopic examined the biochemical tests, PCR, sequencing, homology, and phylogenetic relatedness test. P. multocida was observed as gram negative, coccobacilus, no growth on MacConkey Agar, does not produce H2S and gas, nonmotile and indole positive, does not produce urease enzymes, does not use citrate as a carbon source, does not ferment maltose and lactose but it does ferment glucose, sucrose and mannitol. ThepfhaB1gene fragmentfrom buffalo and cattle NTT isolates and also Katha strain vaccine showed DNA band 506 bp. P.multocida isolates from buffalo and cattle in NTT have 91% - 99% score homology with the comparative isolate. The isolate P. multocida from buffalo and cattle in NTT are in one cluster and their phylogenetic relatedness is close to isolates from Iran and India. It is concluded that the pfhaB1gene fragmentof P. multocida from buffalo and cattle isolates have phylogenetic relatedness close and homolog with the other comparative isolates. Keywords: Haemorrhagic Septicaemia; Nusa Tenggara Timur; Pasteurella multocida; pfhaB1gene

Bacillus cereus and rhubarb regulate the intestinal microbiota of sea cucumber (Apostichopus japonicus Selenka): Species-species interaction, network, and stability

The homeostasis of intestinal microbiota plays a key role in host health. Probiotics and medicinal plant can affect the intestinal microbiota homeostasis but poorly understood. Dietary supplementation with Bacillus cereus BC-1 (BC group) and rhubarb (Rheum officinale Bail, RH group) had no significant impacts on the overall composition of intestinal bacterial community of sea cucumber in terms of α-diversity, richness, or evenness compared to Control group, although a significant reduction in Algibacter was observed in BC and RH groups, as well as Flavobacteriaceae in RH group. Based on species-species interaction, intestinal microbiota in Control, BC, and RH groups formed its own characteristic ecological network model, in which dominant microbes was the main component. In the network, some operational taxonomic units (OTUs) performed as connectors and module hubs and contributed to maintaining the stability of bacterial community. B. cereus BC-1 and rhubarb supplementation could promote the stability of bacterial community through strengthening the cooperative interactions between species, facilitating OTUs to form larger sub-modules, and increasing the number of module hubs. Collaboration between bacteria species could enhance bacterial metabolism and promote digestion of nutrients. B. cereus BC-1 supplementation could improve utilization of feed by increasing microbial fermentation of starch, sucrose and protein, and rhubarb improved microbial metabolism involved in carbohydrate and protein metabolism and reduced microbial lipid metabolism. Generally, our results suggested that though dietary supplementation with B. cereus BC-1 and rhubarb had no significant impacts on the composition of bacterial community, they promoted the homeostasis of intestinal microbiota by affecting interspecific interactions within bacterial community, and then improved the capacity of nutrient digestion of intestinal microbiota.

Aktivitas Antibakteri Ekstrak Batang Kecombrang (Etlingera elatior (Jack) R.M.Sm.) Terhadap Bakteri Plak Gigi Streptococcus mutans

Dental plaques are formed by biofilms that cover the surface of the tooth. Biofilm is a mucous layer consisting of millions of bacterial cells, saliva and food scraps. When biofilm formation is out of control, it will easily thicken on the tooth surface called plaque. This biofilm is a good place for colonization and growth of various types of bacteria, one of which is the Sterpotococcus mutans bacteria. S. mutans bacteria can form colonies that are firmly attached to the tooth surface and are cariogenic bacteria that are able to ferment sucrose (carbohydrates) into acid, reduce the pH of the tooth surface and cause tooth mineralization. So for the control of these bacteria, preparations containing antibacterials are used, one of which is natural ingredients, namely Kecombrang. The aim of this study was to determine the antibacterial activity of the Etlingera elatior (Jack) R.M.Sm. stem extract extracted by solvent based on the level of polarity. Antibacterial activity testing of extracts was divided into 5 groups, namely for n-hexane, ethyl acetate, ethanol extract 20, 40, 60 and 80%, positive control of minosep and negative control (DMSO). The test results showed that E. elatior (Jack) RMSm.) contained secondary metabolites of flavonoids, tannins, saponins, triterpenoids and alkaloids, ethyl acetate extracts with concentrations of 20, 40, 60 and 80%, having strong antibacterial activity against S. mutans of 17.22; 17,55; 17.77 and 18.55 mm, higher than the positive control of Minosep which has antibacterial activity of 16.55 mm.

The Chaaracteristics Yeast Isolated from Commercial Kefir Grain, Indonesia

The objective of this study was to investigate yeast characteristics obtained from commercial grain kefir from Indonesian. Isolation based on macroscopic morphology and microscopic morphology. The first method of research is activation of kefir grain using 10% reconstitution milk, yeast growth on Potato Dextrose Agar (PDA-Agar) medium, yeast coloration by using Lactophenol cotton blue. Then, yeast identification was done by macroscopic and microscopic morphology. Macroscopic morphological observations are observations of colony morphology at the time of isolation and purification, including size, shape, texture, color, surface, elevation, and edges. Microscopic morphological observations include cell shape, budding (budding) which first make preparations with yeast coloring then observed with Zeiss Asio Imager A2 Microscope using Zeiss Axiocam HRC camera. Macroscopic observation of yeast size description colony very small, small, medium, large, colony form is round, the margin is raised, the elevation is entire, the texture is smooth and surface glistening, cream colony color, and yeast smell characteristic. Microscopic observation seen there is cell nucleus, oval, there is pseudohypa, budding, gram-positive, urea test negative, glucose, lactose, maltose fermentation test positive, sucrose fermentation test negative, growth test on liquid media growth in surface medium (pellicle), and bottom medium (sediment). Based on the morphological observations in macroscopic and microscopic yeast identified genus Saccharomyces.

СОВЕРШЕНСТВОВАНИЕ РЕЦЕПТУРЫ ПИТАТАТЕЛЬНОЙ СРЕДЫ DRIGALSKI LACTOSE AGAR

The purpose of the study is to improve the mix formulation of the Drigalski Lactose Agar breeding ground, produced by AppliChem, and aimed at enterobacteria isolation and differentiation. Development of a new mix formulation for the Drigalski Lactose Agar breeding ground, efficient assessment of cultivation of enterobacteria on its improved base and other breeding grounds used in the laboratory practice by the authors was the task of the study. The im-proved agar Drigalsky differential medium with lactose is recommended for cultivation (isolation) of different enter-obacteria of Enterobacteriaceae family.Differentiation of enterobacteria on improved medium is carried out accord-ing to their ability to ferment lactose, mannitol, glucose, sucrose, gelatin and form hydrogen sulfide. The medium can also be used for sanitary and microbiological examination of environmental objects.The medium can be used also to conduct the ONPG test. The efficiency of cultivation of enterobacteria isolated from various animal species on the most frequently used differential diagnostic medium, including new formulation of the Drigalski Lactose Agar, ranged from 16.28 ± 1.44 to 42.18 ± 4.12 hours. Enterobacteria isolated from farm and wild animals formed colo-nies on improved Drygalsky agar with lactose during 24 hours, and enterobacteria isolated from zoo animals within 
 25-31 hours.

Biological diversity of carbon assimilation among isolates of the yeast Dekkera bruxellensis from wine and fuel-ethanol industrial processes.

Dekkera bruxellensis is considered a spoilage yeast in winemaking, brewing and fuel-ethanol production. However, there is growing evidence in the literature of its biotechnological potential. In this work, we surveyed 29 D. bruxellensis isolates from three countries and two different industrial origins (winemaking and fuel-ethanol production) for the metabolization of industrially relevant sugars. The isolates were characterized by the determination of their maximum specific growth rates, and by testing their ability to grow in the presence of 2-deoxy-d-glucose and antimycin A. Great diversity was observed among the isolates, with fuel-ethanol isolates showing overall higher specific growth rates than wine isolates. Preferences for galactose (three wine isolates) and for cellobiose or lactose (some fuel-ethanol isolates) were observed. Fuel-ethanol isolates were less sensitive than wine isolates to glucose catabolite repression (GCR) induction by 2-deoxy-d-glucose. In strictly anaerobic conditions, isolates selected for having high aerobic growth rates were able to ferment glucose, sucrose and cellobiose at fairly high rates without supplementation of casamino acids or yeast extract in the culture medium. The phenotypic diversity found among wine and fuel-ethanol isolates suggests adaptation to these environments. A possible application of some of the GCR-insensitive, fast-growing isolates in industrial processes requiring co-assimilation of different sugars is considered.