scholarly journals Influence of Culture Conditions and Medium Compositions on the Production of Bacteriocin-Like Inhibitory Substances by Lactococcus lactis Gh1

2020 ◽  
Vol 8 (10) ◽  
pp. 1454
Author(s):  
Roslina Jawan ◽  
Sahar Abbasiliasi ◽  
Joo Shun Tan ◽  
Shuhaimi Mustafa ◽  
Murni Halim ◽  
...  
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Lactococcus Lactis ◽  
Organic Nitrogen ◽  
Specific Growth ◽  
Cell Concentration ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Culture Conditions ◽  
Initial Ph

Antibacterial peptides or bacteriocins produced by many strains of lactic acid bacteria have been used as food preservatives for many years without any known adverse effects. Bacteriocin titres can be modified by altering the physiological and nutritional factors of the producing bacterium to improve the production in terms of yield and productivity. The effects of culture conditions (initial pH, inoculum age and inoculum size) and medium compositions (organic and inorganic nitrogen sources; carbon sources) were assessed for the production of bacteriocin-like inhibitory substances (BLIS) by Lactococcus lactis Gh1 in shake flask cultures. An inoculum of the mid-exponential phase culture at 1% (v/v) was the optimal age and size, while initial pH of culture media at alkaline and acidic state did not show a significant impact on BLIS secretion. Organic nitrogen sources were more favourable for BLIS production compared to inorganic sources. Production of BLIS by L. lactis Gh1 in soytone was 1.28-times higher as compared to that of organic nitrogen sources ((NH4)2SO4). The highest cell concentration (XmX = 0.69 ± 0.026 g·L−1) and specific growth rate (μmax = 0.14 h−1) were also observed in cultivation using soytone. By replacing carbon sources with fructose, BLIS production was increased up to 34.94% compared to BHI medium, which gave the biomass cell concentration and specific growth rate of 0.66 ± 0.002 g·L−1 and 0.11 h−1, respectively. It can be concluded that the fermentation factors have pronounced influences on the growth of L. lactis Gh1 and BLIS production. Results from this study could be used for subsequent application in process design and optimisation for improving BLIS production by L. lactis Gh1 at larger scale.

scholarly journals Role of Nutrient Limitation and Stationary-Phase Existence in Klebsiella pneumoniae Biofilm Resistance to Ampicillin and Ciprofloxacin

2003 ◽  
Vol 47 (4) ◽  
pp. 1251-1256 ◽  
Author(s):  
Jeff N. Anderl ◽  
Jeff Zahller ◽  
Frank Roe ◽  
Philip S. Stewart
Keyword(s):  
Growth Rate ◽  
Klebsiella Pneumoniae ◽  
Stationary Phase ◽  
Specific Growth Rate ◽  
Nutrient Limitation ◽  
Prolonged Exposure ◽  
Specific Growth ◽  
Nitrogen Sources ◽  
Biofilm Bacteria ◽  
Bacterial Aggregates

ABSTRACT Biofilms formed by Klebsiella pneumoniae resisted killing during prolonged exposure to ampicillin or ciprofloxacin even though these agents have been shown to penetrate bacterial aggregates. Bacteria dispersed from biofilms into medium quickly regained most of their susceptibility. Experiments with free-floating bacteria showed that stationary-phase bacteria were protected from killing by either antibiotic, especially when the test was performed in medium lacking carbon and nitrogen sources. These results suggested that the antibiotic tolerance of biofilm bacteria could be explained by nutrient limitation in the biofilm leading to stationary-phase existence of at least some of the cells in the biofilm. This mechanism was supported by experimental characterization of nutrient availability and growth status in biofilms. The average specific growth rate of bacteria in biofilms was only 0.032 h−1 compared to the specific growth rate of planktonic bacteria of 0.59 h−1 measured in the same medium. Glucose did not penetrate all the way through the biofilm, and oxygen was shown to penetrate only into the upper 100 μm. The specific catalase activity was elevated in biofilm bacteria to a level similar to that of stationary-phase planktonic cells. Transmission electron microscopy revealed that bacteria were affected by ampicillin near the periphery of the biofilm but were not affected in the interior. Taken together, these results indicate that K. pneumoniae in this system experience nutrient limitation locally within the biofilm, leading to zones in which the bacteria enter stationary phase and are growing slowly or not at all. In these inactive regions, bacteria are less susceptible to killing by antibiotics.

An approach for estimating the maximum specific growth rate of Gluconobacter japonicus in strawberry purée without cell concentration data

2016 ◽  
Vol 105 ◽  
pp. 314-320 ◽  
Author(s):  
A.M. Cañete-Rodríguez ◽  
I.M. Santos-Dueñas ◽  
J.E. Jiménez-Hornero ◽  
M.J. Torija-Martínez ◽  
A. Mas ◽  
...  
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Cell Concentration ◽  
Maximum Specific Growth Rate ◽  
Concentration Data

Impact of Nitrogen Source on the Growth, Specific Growth Rate and Lipid Synthesis of Monoraphidium sp.FXY-10 under Different Culture Conditions

2013 ◽  
Vol 864-867 ◽  
pp. 71-78
Author(s):  
Ke Ding ◽  
Tao Li ◽  
Peng Zhao ◽  
Lin Wang ◽  
Xu Ya Yu
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Nitrogen Source ◽  
Lipid Content ◽  
Specific Growth ◽  
Lipid Synthesis ◽  
Culture Conditions ◽  
Optimal Conditions ◽  
Maximum Biomass ◽  
The Impact

The NaNO3concentration influencing the growth and lipid synthesis ofMonoraphidiumsp.FXY-10 under three cultures (autotrophy, heterotrophy and mixotrophy) was studied through flask-shaking experiment. Additionally, the impact of nitrogen source on the growth and lipid content ofMonoraphidiumsp.FXY-10 was investigated. The NaNO3concentration for maximum biomass and highest lipid content ofMonoraphidiumsp.FXY-10 was obtained and the optimal conditions for its N absorption were concluded through the Andrew model.

scholarly journals Evaluation of the mycelial growth of Trametes villosa (Sw.) Kreisel in media supplemented with copper (II) and sugarcane vinasse

2018 ◽  
pp. 153-160
Author(s):  
Rosa Elena Caballero ◽  
Mónica Miranda ◽  
Víctor Jiménez ◽  
Pedro González ◽  
Tina Hofmann
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Mycelial Growth ◽  
Specific Growth ◽  
Culture Conditions ◽  
Logistic Equation ◽  
Essential Information ◽  
Sugarcane Vinasse ◽  
Different Levels ◽  
Area Data

Se evaluó el efecto de distintos niveles de cobre (II) sobre la velocidad específica de crecimiento de Trametes villosa en medio PDA 4% y medio PDA 4% con 25% (v/v) de vinaza. La velocidad específica de crecimiento se obtuvo a partir de los datos de área micelial y de la ecuación para el modelo logístico de crecimiento. Las mejores condiciones para el crecimiento micelial fueron PDA 4% con 25% (v/v) de vinaza y niveles de cobre divalente de 0,5 y 1,0 mM. Estos resultados indican que, de acuerdo con las condiciones de cultivo utilizadas, ambos suplementos favorecen el crecimiento micelial y entregan información esencial para el desarrollo de potenciales procesos de reutilización y valorización de la vinaza. The effect of different levels of copper (II) on the specific growth rate of Trametes villosa was evaluated. The strain was grown on 4% PDA and 4% PDA on a 25% (v/v) vinasse dilution. The specific growth rate was obtained from the mycelial area data which was modeled with the logistic equation. The best growth condition was 4% PDA in a 25% (v/v) vinasse dilution with copper (II) concentrations of 0.5 and 1.0 mM. These results indicate that under the utilized culture conditions, both supplements favor mycelial growth and provide essential information for potential processes of vinasse reuse and valorization.

scholarly journals BAKTERI M2 PENGHASIL PHB (Polyhydroxybutirate) YANG DIISOLASI DARI PULAU LAKI, KEPULAUAN SERIBU

2016 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Dyah Supryati
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Salinity Tolerance ◽  
Doubling Time ◽  
Specific Growth ◽  
Carbon Sources ◽  
Important Material ◽  
Aerobic Process ◽  
Phb Production ◽  
Electron Sink

Polyhydroxybutirate Producing Bacteria M2 Isolated From Pulau Laki, KepulauanSeribu. PHB is one of very important material for production of biodegradable plastic,and physiologically it is important electron sink in anaerobic-aerobic process. PHB accumulating bacteria M2 was isolated from mangrove of Pulau Laki, Kepulauan Seribu.The bacteria were able to produce PHB from glucose, acetate, and sucrose .Strain M2 was produced PHB (79.9% of biomass) by using acetate as sole carbon sources. The strain was also able to grow at 3 % to 5 % with a doubling time of 10.9 and 21.04 hours and specific growth rate (0.0633 h-1 and 0.0328 h-1). The ability of Strain M2 to produce PHB and its salinity tolerance implying that this strain is not only importance for PHB production but also ecologically importance microbe.Key word: PHB accumulating bacteria, marine, salinity tolerance

scholarly journals Optimization of Culture Conditions on Growth of Chlorella sp. Newly Isolated From Bagansiapiapi Waters Indonesia

2021 ◽  
Vol 934 (1) ◽  
pp. 012097
Author(s):  
D Iriani ◽  
B Hasan ◽  
HS Putra ◽  
TM Ghazali
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Cell Density ◽  
Specific Growth ◽  
Pharmaceutical Products ◽  
Culture Conditions ◽  
Marine Waters ◽  
Chlorella Sp ◽  
Need To Evaluate ◽  
Further Development

Abstract Chlorella sp. is a type of micro-sized green algae obtained in fresh or marine waters. However, many factors need to evaluate the growth of Chlorella sp. mainly the culture conditions. This study aimed to evaluate the culture conditions in optimizing the growth of Chlorella sp. newly isolated from Bagansiapiapi marine waters. The experiment was carried out at temperature ±25°C, light intensity 2300 Lux using TL-D lamp (36 W). There were six treatments as culture conditions for the cultivation of Chlorella sp.:1). Bean Sprouts (Vigna radiata) Extract Media (BSEM) with light continuously, 2. BSEM with a Photoperiod light:dark (10:14h), 3. Tofu waste media with light continuously, 4. Tofu waste media with a photoperiod light:dark (10: 14h), 5. Fish pellet solutions media (25%), 6. Fish pellet solutions media (50%). The parameter observed was the growth, cell density and the specific growth rate of Chlorella sp. every 2 days for 14 days of cultivation. Based on the results shown that the marine Chlorella sp. from Bagansiapiapi waters could be adapted to all treatments. Nevertheless, the use of BSEM light continuously obtained the highest cell density (27.75 x 105 cell/ml) on 12 days and continues to increase until 14 days, while the other treatments had decreased. Furthermore, the Chlorella sp. obtained the specific growth rate was 0.42. Therefore, the marine Chlorella sp. from Bagansiapiapi could be cultivated in BSEM light continuously for further development as a functional food or bioactive source in pharmaceutical products.

scholarly journals The effect of application of semimoist feeding mixture when converting the advanced fry of zander (Sander lucioperca) to intensive culture conditions

2007 ◽  
Vol 55 (1) ◽  
pp. 17-24
Author(s):  
Vít Baránek ◽  
Jan Mareš ◽  
Jiří Jirásek ◽  
Miroslav Prokeš ◽  
Petr Spurný
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Direct Conversion ◽  
Culture Conditions ◽  
Intensive Culture ◽  
Sander Lucioperca ◽  
Zander Sander Lucioperca ◽  
Conversion Performance ◽  
Fish Survival

Conversion success of pond-reared zander (Sander lucioperca) fry was evaluated using three different converting methods: direct conversion to dry feed (Bio-Optimal Start 0.8 mm; variant A), three–day application of semimoist feeding mixture on the base of fish (variant B) and three-day application of semimoist mixture + three-day co-feeding of semimoist mixture and dry feed (variant C). Two replicates per treatment were applied. These three methods were evaluated regarding specific growth rate (SGR), condition coefficient (K), survival and cannibalism. Mean initial total length (TL) of fish was 35.22 ± 2.15 mm and mean individual weight (w) was 0.31 ± 0.05 g. There were 600 individuals in each circular tank. The initial stock density was 2 fish.l – 1. Fish survival during a 14-day period of rearing ranged from 34.33 % (variant C) to 50.33 % (variant A). Significantly (P < 0.05) better conversion performance was achieved with variants A and B than with the variant C regarding all parameters.

scholarly journals Kinetic Modelling of Lovastatin Biosynthesis by Aspergillus Terreus Cultivated on Lactose and Glycerol as Carbon Sources

2012 ◽  
Vol 33 (4) ◽  
pp. 651-665 ◽  
Author(s):  
Marta Pawlak ◽  
Marcin Bizukojć
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Kinetic Model ◽  
Organic Nitrogen ◽  
Aspergillus Terreus ◽  
Specific Growth ◽  
Kinetic Modelling ◽  
Carbon Sources ◽  
Batch Experiments ◽  
Kinetics Of

A kinetic model to describe lovastatin biosynthesis by Aspergillus terreus ATCC 20542 in a batch culture with the simultaneous use of lactose and glycerol as carbon sources was developed. In order to do this the kinetics of the process was first studied. Then, the model consisting of five ordinary differential equations to balance lactose, glycerol, organic nitrogen, lovastatin and biomass was proposed. A set of batch experiments with a varying lactose to glycerol ratio was used to finally establish the form of this model and find its parameters. The parameters were either directly determined from the experimental data (maximum biomass specific growth rate, yield coefficients) or identified with the use of the optimisation software. In the next step the model was verified with the use of the independent sets of data obtained from the bioreactor cultivations. In the end the parameters of the model were thoroughly discussed with regard to their biological sense. The fit of the model to the experimental data proved to be satisfactory and gave a new insight to develop various strategies of cultivation of A. terreus with the use of two substrates.

scholarly journals Protein turnover forms one of the highest maintenance costs in Lactococcus lactis

Microbiology ◽  
2014 ◽  
Vol 160 (7) ◽  
pp. 1501-1512 ◽  
Author(s):  
Petri-Jaan Lahtvee ◽  
Andrus Seiman ◽  
Liisa Arike ◽  
Kaarel Adamberg ◽  
Raivo Vilu
Keyword(s):  
Growth Rate ◽  
Total Energy ◽  
Specific Growth Rate ◽  
Lactococcus Lactis ◽  
Protein Turnover ◽  
Biomass Yield ◽  
Specific Growth ◽  
High Energy ◽  
Turnover Rates ◽  
Maintenance Costs

Protein turnover plays an important role in cell metabolism by regulating metabolic fluxes. Furthermore, the energy costs for protein turnover have been estimated to account for up to a third of the total energy production during cell replication and hence may represent a major limiting factor in achieving either higher biomass or production yields. This work aimed to measure the specific growth rate (μ)-dependent abundance and turnover rate of individual proteins, estimate the ATP cost for protein production and turnover, and compare this with the total energy balance and other maintenance costs. The lactic acid bacteria model organism Lactococcus lactis was used to measure protein turnover rates at μ = 0.1 and 0.5 h−1 in chemostat experiments. Individual turnover rates were measured for ~75 % of the total proteome. On average, protein turnover increased by sevenfold with a fivefold increase in growth rate, whilst biomass yield increased by 35 %. The median turnover rates found were higher than the specific growth rate of the bacterium, which suggests relatively high energy consumption for protein turnover. We found that protein turnover costs alone account for 38 and 47 % of the total energy produced at μ = 0.1 and 0.5 h−1, respectively, and gene ontology groups Energy metabolism and Translation dominated synthesis costs at both growth rates studied. These results reflect the complexity of metabolic changes that occur in response to changes in environmental conditions, and signify the trade-off between biomass yield and the need to produce ATP for maintenance processes.

Sign in / Sign up

Export Citation Format

Share Document