scholarly journals A Novel Carboxylesterase Derived from a Compost Metagenome Exhibiting High Stability and Activity towards High Salinity

Genes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 122
Author(s):  
Mingji Lu ◽  
Rolf Daniel
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
High Salinity ◽  
Functional Screening ◽  
Lipolytic Enzymes ◽  
Acidic Residues ◽  
Lysine Residues ◽  
Potential Applications ◽  
Harsh Conditions

Halotolerant lipolytic enzymes have gained growing interest, due to potential applications under harsh conditions, such as hypersalinity and presence of organic solvents. In this study, a lipolytic gene, est56, encoding 287 amino acids was identified by functional screening of a compost metagenome. Subsequently, the gene was heterologously expressed, and the recombinant protein (Est56) was purified and characterized. Est56 is a mesophilic (Topt 50 °C) and moderate alkaliphilic (pHopt 8) enzyme, showing high thermostability at 30 and 40 °C. Strikingly, Est56 is halotolerant as it exhibited high activity and stability in the presence of up to 4 M NaCl or KCl. Est56 also displayed enhanced stability against high temperatures (50 and 60 °C) and urea (2, 4, and 6 M) in the presence of NaCl. In addition, the recently reported halotolerant lipolytic enzymes were summarized. Phylogenetic analysis grouped these enzymes into 13 lipolytic protein families. The majority (45%) including Est56 belonged to family IV. To explore the haloadaptation of halotolerant enzymes, the amino acid composition between halotolerant and halophilic enzymes was statistically compared. The most distinctive feature of halophilic from non-halophilic enzymes are the higher content of acidic residues (Asp and Glu), and a lower content of lysine, aliphatic hydrophobic (Leu, Met and Ile) and polar (Asn) residues. The amino acid composition and 3-D structure analysis suggested that the high content of acidic residues (Asp and Glu, 12.2%) and low content of lysine residues (0.7%), as well as the excess of surface-exposed acidic residues might be responsible for the haloadaptation of Est56.

Dentine is biochemically abnormal in osteogenesis imperfecta

1986 ◽  
Vol 70 (4) ◽  
pp. 339-346 ◽  
Author(s):  
John P. Gage ◽  
Martin J. O. Francis ◽  
Gill E. Whitaker ◽  
Roger Smith
Keyword(s):  
Amino Acid ◽  
Osteogenesis Imperfecta ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
High Frequency ◽  
Permanent Teeth ◽  
Type I ◽  
Clinically Normal ◽  
Lysine Residues ◽  
Biochemical Abnormalities

1. In osteogenesis imperfecta the bones are brittle but the teeth, whose dentine contains the same genetic collagen as bone (type I), may be clinically normal. 2. To investigate this paradox we have measured the amino acid composition of insoluble dentine collagen from 16 deciduous and 18 permanent teeth in control subjects and in 59 patients with different forms of osteogenesis imperfecta. 3. In 55 of the patient samples significant differences from normal were found, especially in the number of lysine residues, and in the relative amounts of hydroxylysine to lysine. 4. These results demonstrate the high frequency of biochemical abnormalities in osteogenesis imperfecta. They also suggest that classifications of this disorder based on the presence or absence of clinical dentiogenesis imperfecta are likely to be unsound.

Effect of maternal diet on the amino acid composition of human uterine fluid

2014 ◽  
Author(s):  
Alexandra Jayne Kermack ◽  
Ying Cheong ◽  
Nick Brook ◽  
Nick Macklon ◽  
Franchesca D Houghton
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Maternal Diet ◽  
Uterine Fluid

Biological Processing of Pea Grain and Secondary Starch Raw Materials to Produce Food and Feed Protein Concentrates

2020 ◽  
Vol 36 (4) ◽  
pp. 49-58
Author(s):  
V.V. Kolpakova ◽  
R.V. Ulanova ◽  
L.V. Chumikina ◽  
V.V. Bessonov
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Mass Fraction ◽  
Geotrichum Candidum ◽  
Protein Concentrate ◽  
Protein Concentrates ◽  
Pea Flour ◽  
Nitrogenous Substances

The goal of the study was to develop a biotechnological process for the production of protein concentrates via bioconversion of pea flour and whey, a secondary product of starch manufacture. Standard and special methods were used to analyze the chemical and biochemical composition of protein concentrates (amino acid, carbohydrate, and fractional) of flour, whey and protein concentrates. It was established that pea flour contains 52.28-57.05% water-soluble nitrogenous substances, 23.04-25.50% salt-soluble, 2.94-4.69% alcohol-soluble compounds, 0-0.61% of soluble glutenine, 6.67-10.40% alkali-soluble glutenine and 5.96-10.86% insoluble sclerotic substances. A mathematical model and optimal parameters of the enzymatic extraction of pea protein with a yield of 65-70% were developed. Ultrasonic exposure increased the yield of nitrogenous substances by 23.16 ± 0.69%, compared with the control without ultrasound. The protein concentrate had a mass fraction of nitrogenous substances of 72.48 ± 0.41% (Nx6.25) and a complete amino acid composition. The microbial conversion by the Saccharomyces cerevisiae 121 and Geotrichum candidum 977 cultures of starch whey which remained after protein precipitation allowed us to obtain feed concentrates from biomass and culture liquid with a protein mass fraction of 61.68-70.48% (Nx6.25). Protein concentrates positively affected the vital signs of rats and their excretory products. A technological scheme was developed to test the complex pea grain and starch whey processing under pilot conditions. pea, protein concentrate, extracts, whey, bioconversion, Geotrichum candidum, Saccharomyces cerevisiae, chemical composition, amino acid composition

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