optimal growth
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Fermentation ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 35
Elizaveta Timkina ◽  
Lucie Drábová ◽  
Andrea Palyzová ◽  
Tomáš Řezanka ◽  
Olga Maťátková ◽  

Members of the genus Kocuria are often found in soils contaminated with toxic metals or exposed to high levels of ionizing radiation. The use of classical cultivation technics often leads to the isolation of Kocuria sp. from underground spring waters. These bacterial isolates have to adapt their metabolism to survive in such extreme environments. Four bacterial isolates of the genus Kocuria (Kocuria sp. 101, 208, 301, and 401) were obtained from radon spring water (Jachymov, Czech Republic). These isolates were tested for their ability to withstand stress and extreme conditions. Growth was observed at a temperature range of 10–45 °C with optimal growth temperature between 20 and 30 °C. The content of polyunsaturated fatty acids in all four isolates was proved to be temperature-dependent. The strain Kocuria sp. 301 showed high resistance to all studied extreme conditions (UV radiation, desiccation, and free radicals in medium). The results suggest that isolates from radioactive springs might have developed mechanisms that help them survive under several extreme conditions and could be used in biotechnological production.

eLife ◽  
2022 ◽  
Vol 11 ◽  
Catherine Stark ◽  
Teanna Bautista-Leung ◽  
Joanna Siegfried ◽  
Daniel Herschlag

Cold temperature is prevalent across the biosphere and slows the rates of chemical reactions. Increased catalysis has been predicted to be a dominant adaptive trait of enzymes to reduced temperature, and this expectation has informed physical models for enzyme catalysis and influenced bioprospecting strategies. To systematically test rate enhancement as an adaptive trait to cold, we paired kinetic constants of 2223 enzyme reactions with their organism’s optimal growth temperature (TGrowth) and analyzed trends of rate constants as a function of TGrowth. These data do not support a general increase in rate enhancement in cold adaptation. In the model enzyme ketosteroid isomerase (KSI), there is prior evidence for temperature adaptation from a change in an active site residue that results in a tradeoff between activity and stability. Nevertheless, we found that little of the rate constant variation for 20 KSI variants was accounted for by TGrowth. In contrast, and consistent with prior expectations, we observed a correlation between stability and TGrowth across 433 proteins. These results suggest that temperature exerts a weaker selection pressure on enzyme rate constants than stability and that evolutionary forces other than temperature are responsible for the majority of enzymatic rate constant variation.

2022 ◽  
Vol 12 ◽  
Thomas Klaus ◽  
Sabrina Ninck ◽  
Andreas Albersmeier ◽  
Tobias Busche ◽  
Daniel Wibberg ◽  

Activity-based protein profiling (ABPP) has so far scarcely been applied in Archaea in general and, especially, in extremophilic organisms. We herein isolated a novel Thermococcus strain designated sp. strain 2319x1E derived from the same enrichment culture as the recently reported Thermococcus sp. strain 2319x1. Both strains are able to grow with xylan as the sole carbon and energy source, and for Thermococcus sp. strain 2319x1E (optimal growth at 85°C, pH 6–7), the induction of xylanolytic activity in the presence of xylan was demonstrated. Since the solely sequence-based identification of xylanolytic enzymes is hardly possible, we established a complementary approach by conducting comparative full proteome analysis in combination with ABPP using α- or β-glycosidase selective probes and subsequent mass spectrometry (MS)-based analysis. This complementary proteomics approach in combination with recombinant protein expression and classical enzyme characterization enabled the identification of a novel bifunctional maltose-forming α-amylase and deacetylase (EGDIFPOO_00674) belonging to the GH57 family and a promiscuous β-glycosidase (EGIDFPOO_00532) with β-xylosidase activity. We thereby further substantiated the general applicability of ABPP in archaea and expanded the ABPP repertoire for the identification of glycoside hydrolases in hyperthermophiles.

Mozzamil Mohammed ◽  
Bernd Blasius ◽  
Alexey Ryabov

AbstractThe dynamics of trait-based metacommunities have attracted much attention, but not much is known about how dispersal and spatial environmental variability mutually interact with each other to drive coexistence patterns and diversity. Here, we present a spatially explicit model of competition for two essential resources in a metacommunity on a one-dimensional environmental gradient. We find that both the strength of dispersal and the range of spatial environmental variability affect coexistence patterns, spatial structure, trait distribution, and local and regional diversity. Without dispersal, species are sorted according to their optimal growth conditions on the gradient. With the onset of dispersal, source-sink effects are initiated, which increases the effects of environmental filtering and interspecific competition and generates trait lumping, so that only a few species from an environment-defined trait range can survive. Interestingly, for very large dispersal rates, species distributions become spatially homogeneous, but nevertheless two species at the extreme ends of the trade-off curve can coexist for large environmental variability. Local species richness follows a classic hump-shaped dependence on dispersal rate, while local and regional diversity exhibit a pronounced peak for intermediate values of the environmental variability. Our findings provide important insights into the factors that shape the structure of trait-based metacommunities.

Claudia F. Dick ◽  
Nathália Rocco-Machado ◽  
André L. A. Dos-Santos ◽  
Luiz F. Carvalho-Kelly ◽  
Carolina L. Alcantara ◽  

The parasite Trypanosoma cruzi causes Chagas’ disease; both heme and ionic Fe are required for its optimal growth, differentiation, and invasion. Fe is an essential cofactor in many metabolic pathways. Fe is also harmful due to catalyzing the formation of reactive O2 species; for this reason, all living systems develop mechanisms to control the uptake, metabolism, and storage of Fe. However, there is limited information available on Fe uptake by T. cruzi. Here, we identified a putative 39-kDa Fe transporter in T. cruzi genome, TcIT, homologous to the Fe transporter in Leishmania amazonensis and Arabidopsis thaliana. Epimastigotes grown in Fe-depleted medium have increased TcIT transcription compared with controls grown in regular medium. Intracellular Fe concentration in cells maintained in Fe-depleted medium is lower than in controls, and there is a lower O2 consumption. Epimastigotes overexpressing TcIT, which was encountered in the parasite plasma membrane, have high intracellular Fe content, high O2 consumption—especially in phosphorylating conditions, high intracellular ATP, very high H2O2 production, and stimulated transition to trypomastigotes. The investigation of the mechanisms of Fe transport at the cellular and molecular levels will assist in elucidating Fe metabolism in T. cruzi and the involvement of its transport in the differentiation from epimastigotes to trypomastigotes, virulence, and maintenance/progression of the infection.

Md. Raihan Uddin ◽  
Pranab Roy ◽  
Sukhendu Mandal

Polar microbiology remains as the most fascinating area of research which mainly focuses on exploration of psychrophilic organisms for having their cold-active enzymes of biotechnological potential. In this study, we have explored a culturable bacterial community and isolated 27 bacterial isolates with a different morphology from an unexplored site of Arctic region, for the possibility of identifying various active biomolecules. Screening of various isolates in a culture dependent manner helped us to identify strains capable of producing extracellular enzymes. The optimal growth parameters of most of the isolates are ranges between 18-22°C temperature, 3-5 days of incubation, 6-9 pH, and 3-5% (w/v) NaCl in LB media. It has also been found that among these isolates, 63% are able to produce lipase, 17% amylase, 7% xylanase and 7% isolates have responded for phosphatase activity but there are no isolates found for gelatinase and cellulase production ability. In addition, few isolates can also produce secretory protease, urease, β-galactosidase, etc. 16SrRNA gene sequence-based phylogeny revealed that the isolates belong to the genera of Psychrobacter, Planococcus, Halomonas, Arthrobacter, Oceanisphaera, Marinbacter, Pseudomonas, Algoriphagus. Strikingly, none of the Arctic isolates showed resistance towards commonly used antibiotics which indicates that the unexplored habitat is devoid of antibiotic exposure and so does the rise of antimicrobial resistance. The structure-function relationship of the isolated bioactive compounds from these isolates are the major focus of future research.

2022 ◽  
Vol 8 ◽  
Shui-Kai Chang ◽  
Tzu-Lun Yuan ◽  
Simon D. Hoyle ◽  
Jessica H. Farley ◽  
Jen-Chieh Shiao

Growth shapes the life history of fishes. Establishing appropriate aging procedures and selecting representative growth models are important steps in developing stock assessments. Flyingfishes (Exocoetidae) have ecological, economic, and cultural importance to many coastal countries including Taiwan. There are 29 species of flyingfishes found in the Kuroshio Current off Taiwan and adjacent waters, comprising 56% of the flyingfishes taxa recorded worldwide. Among the six dominant species in Taiwan, four are of special importance. This study reviews aging data of these four species, documents major points of the aging methods to address three aging issues identified in the literature, and applies multi-model inference to estimate sex-combined and sex-specific growth parameters for each species. The candidate growth models examined included von Bertalanffy, Gompertz, Logistic, and Richards models, and the resulting optimal model tended to be the von Bertalanffy model for sex-combined data and Gompertz and von Bertalanffy models for sex-specific cases. The study also estimates hatch dates from size data collected from 2008 to 2017; the results suggest that the four flyingfishes have two spawning seasons per year. Length-weight relationships are also estimated for each species. Finally, the study combines the optimal growth estimates from this study with estimates for all flyingfishes published globally, and statistically classifies the estimates into clusters by hierarchical clustering analysis of logged growth parameters. The results demonstrate that aging materials substantially affect growth parameter estimates. This is the first study to estimate growth parameters of flyingfishes with multiple model consideration. This study provides advice for aging flyingfishes based on the three aging issues and the classification analysis, including a recommendation of using the asterisci for aging flyingfishes to avoid complex otolith processing procedures, which could help researchers from coastal countries to obtain accurate growth parameters for many flyingfishes.

2022 ◽  
Hammed Ayansola ◽  
Xiaoxiao Yu ◽  
Jiaqi Lei ◽  
Chaoyong Liao ◽  
Yuming Guo ◽  

Abstract Background: Ad libitum (AD) feeding is crucial to profitable commercial broiler chicken production. However, it partly disrupts muscle development, causing myopathies like white striping in broilers’ breast meat. For this reason, this study investigated the impacts of intermittent feeding (IF) and fasting strategies as potential alternatives to AD feeding. A total of 384 one-day-old broilers were randomly allotted into 4 groups - ad libitum, 1h-IF group (4 times/day, 1 hour each time), 1.5h-IF (4 times/day, 1.5hrs each time), and acute fasting (1-day acute fasting, 6-days free access to feed). Feed intake, weight gain, muscle structure, differential genes, and protein expressions were assessed in the broiler breast muscles. Results: IF and fasting significantly reduced ectopic fat deposit and muscle fiber size (p < 0.05). Notably, 1.5h-IF promoted PAX7+ satellite cell proliferation supporting muscle growth and repair activities in fast-growth broiler chickens. Consistently, the restricted regimens downregulated the collagen protein synthesis of skeletal muscle-specific E3 ubiquitin ligases (TRIM63 and MAFBX) in 42 – days old breast muscle samples (p < 0.05), especially in the 1.5h-IF group. Compared to AD-fed birds, 1.5h-IF and fasting feeding significantly decreased white striping scores in the breast meat muscle (p < 0.05). ConclusionChronic IF or acute fasting improved muscle health of broiler chickens without significant compromise on growth rate and feed efficiency compared to AD feeding. Therefore, this study presents potential feeding frequencies relevant for optimal growth pace while alleviating the occurrence of myopathic pathophysiology in broiler chickens.

2022 ◽  
Vol 4 (2) ◽  
pp. 1107-1114
Citra Windani Mambang Sari ◽  
Iwan Shalahuddin ◽  
Iqbal Pramukti

Health promotion in schools is a strategic step in improving public health. This is because health promotion through the school community is quite effective in increasing public awareness in carrying out clean and healthy living behaviors. School age is very good for providing education and understanding about Clean and Healthy Life Behavior (PHBS), one of which is education about nutrition. Optimal nutrition intake, both in terms of quantity and quality, is very important for optimal growth and development. For this reason, our diet needs to be improved towards the consumption of balanced nutrition. Balanced nutrition is a balanced diet of daily food that contains nutrients in the type and amount according to the body's needs. The purpose of the activity is to create students, teachers and the school environment community to implement PHBS, create a healthy, clean and comfortable school environment, be able to improve education in schools, create health services in schools that can be put to good use, especially nutrition action. The method used is the lecture method via whatsapp, poster installation, question and answer and group discussion. The results of the health education activities were approximately 67 participants. The counseling participants looked enthusiastic when the material was given. Participants participated in the counseling happily because the counseling was carried out in a fun way. The counseling activity was conducive because the participants paid attention to the material presented well. This is evidenced by the number of participants who are interested in answering questions during the question and answer session. Participants participated in the counseling happily because the counseling was carried out using a fun online method. Counseling activities are conducive because the community pays attention to the material presented well

2022 ◽  
Vol 4 (2) ◽  
pp. 984-988
Juni Sofiana ◽  
Hastin Ika Indriyastuti ◽  
Melisha Situmorang

Children are the nation's most valuable asset in the future, monitoring and stimulation of growth and development is one way for children to achieve optimal growth and development. Every child needs to be stimulated and monitored regularly as early as possible appropriately and continuously, both in the family and at school. Monitoring growth and development is carried out to find out whether children grow and develop according to their age and stage of development and can detect deviations in child growth and development. The purpose of this community service is to increase knowledge and provide training to early childhood teachers regarding early detection of child growth and development. This community service method is to conduct counseling about growth and development and early detection, followed by training for early detection of growth and development. Community service results: Pretest results show that of the 35 early childhood teachers who participated in the activity, 13 teachers had poor knowledge, and 12 teachers had sufficient knowledge, and 10 teachers had good knowledge. The results of the posttest after the counseling were 35 early childhood teachers who had good knowledge. The conclusion of community service is: There is an increase in knowledge after counseling on growth and development and early detection.

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