scholarly journals Pengaruh Fermentasi Fungi, Bakteri Asam Laktat dan Khamir terhadap Kualitas Nutrisi Tepung Sorgum (Effect of Lactic Acid Bacteria, Fungi and Yeast Fermentation on Nutritional Quality of Sorghum Flour)

2017 ◽  
Vol 36 (4) ◽  
pp. 440 ◽  
Author(s):  
Raden Haryo Bimo Setiarto ◽  
Nunuk Widhyastuti ◽  
Iwan Saskiawan

Recently, food security problem in Indonesia is mainly due to the consumption dependence on rice and wheat, while the utilization of local sources of carbohydrates such as tubers and cereals are still limited. Sorghum is one of local cereal that potential to be developed as source of carbohydrates and protein. However, a problem encountered on utilising sorghum as food is the low protein digestibility. The objective of this study was to investigate the effects of fermentation of Rhizopus oligosporus, Lactobacillus plantarum, and Saccharomyces cerevisiae on nutritional quality and digestibility of sorghum flour. The procedure in this research were pre-treatment of sorghum grains, preparations of inoculum, solid state fermentation, liquid state fermentation, mixture solid-liquid fermentation of sorghum grains, flouring (draining and mashing), microbial (total plate count) and chemical analysis (proximate analysis, amino acid analysis, and protein digestibilty). Sorghum flour was made with 4 variations of treatments that was performed in triplo, i.e: control (without fermentation), liquid fermentation (with Lactobacillus plantarum and Saccharomyces cerevisiae), solid fermentation (with Rhizopus oligosporus), solid and liquid fermentation (with addition of Rhizopus oligosporus,Lactobacillus plantarum and Saccharomyces cerevisiae). The result showed that the number of microbes in fermented sorghum flour was still within the safety limits in accordance to SNI. The fermentation process did not significantly influence the levels of protein, carbohydrate, and fat of sorghum flour. During the fermentation of sorghum, the levels of the amino acids cysteine and lysine increased while several other amino acids decreased. Fermentation increased significantly the digestibility of sorghum protein up to 3,5-5 fold than control without fermentation.ABSTRAKMasalah ketahanan pangan di Indonesia saat ini diantaranya adalah pola konsumsi masyarakat sangat tergantung pada beras, terigu, dan belum luasnya pemanfaatan sumber karbohidrat lokal seperti umbi-umbian dan serealia. Sorgum adalah salah satu serealia lokal yang berpotensi dikembangkan menjadi sumber karbohidrat dan protein. Namun, salah satu kendala yang dihadapi dalam pemanfaatan sorgum sebagai bahan pangan adalah rendahnya daya cerna protein sorgum. Penelitian ini bertujuan menganalisis pengaruh fermentasi Rhizopus oligosporus, Lactobacillus plantarum, dan Saccharomyces cerevisiae terhadap kualitas nutrisi dan daya cerna protein tepung sorgum. Tahapan penelitian yang dilakukan yaitu pra-perlakuan biji sorgum, penyiapan inokulum, fermentasi padat, fermentasi cair, fermentasi campuran padat dan cair terhadap biji sorgum, penepungan (pengeringan dan penggilingan), analisis mikrobiologi (total koloni mikroba) dan analisis kimia (kadar proksimat, asam amino, dan daya cerna protein). Pembuatan tepung sorgum dilakukan dengan empat perlakuan secara triplo yaitu kontrol (tanpa fermentasi), fermentasi cair (dengan Lactobacillus plantarum dan Saccharomyces cerevisiae), fermentasi padat (dengan Rhizopus oligosporus), dan fermentasi campuran padat dan cair (dengan Rhizopus oligosporus, Lactobacillus plantarum dan Saccharomyces cerevisiae). Hasil penelitian menunjukkan bahwa jumlah mikrobia pada tepung sorgum fermentasi masih dalam batas aman sesuai dengan SNI. Proses fermentasi tidak berpengaruh signifikan terhadap kadar protein, karbohidrat, dan lemak pada tepung sorgum. Selama fermentasi sorgum, kadar asam amino sistein dan lisin mengalami peningkatan sedangkan beberapa asam amino lainnya menurun. Proses fermentasi berpengaruh signifikan dalam meningkatkan daya cerna protein sorgum sebesar 3,5-5 kali lipat dibandingkan dengan kontrol tanpa fermentasi.

2020 ◽  
Vol 8 (8) ◽  
pp. 1109
Author(s):  
S. Christine du Toit ◽  
Debra Rossouw ◽  
Maret du Toit ◽  
Florian F. Bauer

Saccharomyces cerevisiae and Lactobacillus plantarum are responsible for alcoholic and malolactic fermentation, respectively. Successful completion of both fermentations is essential for many styles of wine, and an understanding of how these species interact with each other, as well as the development of compatible pairings of these species, will help to manage the process. However, targeted improvements of species interactions are difficult to perform, in part because of the chemical and biological complexity of natural grape juice. Synthetic ecological systems reduce this complexity and can overcome these difficulties. In such synthetic systems, mutualistic growth of different species can be enforced through the reciprocal exchange of essential nutrients. Here, we implemented a novel approach to evolve mutualistic traits by establishing a co-dependent relationship between S. cerevisiae BY4742Δthi4 and Lb. plantarum IWBT B038 by omitting different combinations of amino acids from a chemically defined synthetic medium simulating standard grape juice. After optimization, the two species were able to support the growth of each other when grown in the absence of appropriate combinations of amino acids. In these obligatory mutualistic conditions, BY4742Δthi4 and IWBT B038 were co-evolved for approximately 100 generations. The selected evolved isolates showed improved mutualistic growth and the growth patterns under non-selective conditions indicate the emergence of mutually beneficial adaptations independent of the synthetic selection pressure. The combined use of synthetic ecology and co-evolution is a promising strategy to better understand and biotechnologically improve microbial interactions.


2017 ◽  
Vol 8 (3) ◽  
pp. 1132-1143 ◽  
Author(s):  
Jiayan Zhang ◽  
Xiang Xiao ◽  
Ying Dong ◽  
Lani Shi ◽  
Tian Xu ◽  
...  

Fermented cereals have significant potential for improving the nutritional quality and health effects of foods and ingredients.


1992 ◽  
Vol 12 (5) ◽  
pp. 2154-2164 ◽  
Author(s):  
D J DeMarini ◽  
M Winey ◽  
D Ursic ◽  
F Webb ◽  
M R Culbertson

The SEN1 gene, which is essential for growth in the yeast Saccharomyces cerevisiae, is required for endonucleolytic cleavage of introns from all 10 families of precursor tRNAs. A mutation in SEN1 conferring temperature-sensitive lethality also causes in vivo accumulation of pre-tRNAs and a deficiency of in vitro endonuclease activity. Biochemical evidence suggests that the gene product may be one of several components of a nuclear-localized splicing complex. We have cloned the SEN1 gene and characterized the SEN1 mRNA, the SEN1 gene product, the temperature-sensitive sen1-1 mutation, and three SEN1 null alleles. The SEN1 gene corresponds to a 6,336-bp open reading frame coding for a 2,112-amino-acid protein (molecular mass, 239 kDa). Using antisera directed against the C-terminal end of SEN1, we detect a protein corresponding to the predicted molecular weight of SEN1. The SEN1 protein contains a leucine zipper motif, consensus elements for nucleoside triphosphate binding, and a potential nuclear localization signal sequence. The carboxy-terminal 1,214 amino acids of the SEN1 protein are essential for growth, whereas the amino-terminal 898 amino acids are dispensable. A sequence of approximately 500 amino acids located in the essential region of SEN1 has significant similarity to the yeast UPF1 gene product, which is involved in mRNA turnover, and the mouse Mov-10 gene product, whose function is unknown. The mutation that creates the temperature-sensitive sen1-1 allele is located within this 500-amino-acid region, and it causes a substitution for an amino acid that is conserved in all three proteins.


2021 ◽  
Vol 105 (6) ◽  
pp. 2597-2611
Author(s):  
Xianlin He ◽  
Bo Liu ◽  
Yali Xu ◽  
Ze Chen ◽  
Hao Li

1987 ◽  
Vol 7 (8) ◽  
pp. 2783-2793
Author(s):  
S J Elledge ◽  
R W Davis

Ribonucleotide reductase catalyzes the first step in the pathway for the production of deoxyribonucleotides needed for DNA synthesis. The gene encoding the small subunit of ribonucleotide reductase was isolated from a Saccharomyces cerevisiae genomic DNA expression library in lambda gt11 by a fortuitous cross-reaction with anti-RecA antibodies. The cross-reaction was due to an identity between the last four amino acids of each protein. The gene has been named RNR2 and is centromere linked on chromosome X. The nucleotide sequence was determined, and the deduced amino acid sequence, 399 amino acids, shows extensive homology with other eucaryotic ribonucleotide reductases. Transplason mutagenesis was used to disrupt the RNR2 gene. A novel assay using colony color sectoring was developed to demonstrate visually that RNR2 is essential for mitotic viability. RNR2 encodes a 1.5-kilobase mRNA whose levels increase 18-fold after treatment with the DNA-damaging agent 4-nitroquinoline 1-oxide. CDC8 was also found to be inducible by DNA damage, but POL1 and URA3 were not inducible by 4-nitroquinoline 1-oxide. The expression of these genes defines a new mode of regulation for enzymes involved in DNA biosynthesis and sharpens our picture of the events leading to DNA repair in eucaryotic cells.


1986 ◽  
Vol 6 (5) ◽  
pp. 1711-1721
Author(s):  
E M McIntosh ◽  
R H Haynes

The dCMP deaminase gene (DCD1) of Saccharomyces cerevisiae has been isolated by screening a Sau3A clone bank for complementation of the dUMP auxotrophy exhibited by dcd1 dmp1 haploids. Plasmid pDC3, containing a 7-kilobase (kb) Sau3A insert, restores dCMP deaminase activity to dcd1 mutants and leads to an average 17.5-fold overproduction of the enzyme in wild-type cells. The complementing activity of the plasmid was localized to a 4.2-kb PvuII restriction fragment within the Sau3A insert. Subcloning experiments demonstrated that a single HindIII restriction site within this fragment lies within the DCD1 gene. Subsequent DNA sequence analysis revealed a 936-nucleotide open reading frame encompassing this HindIII site. Disruption of the open reading frame by integrative transformation led to a loss of enzyme activity and confirmed that this region constitutes the dCMP deaminase gene. Northern analysis indicated that the DCD1 mRNA is a 1.15-kb poly(A)+ transcript. The 5' end of the transcript was mapped by primer extension and appears to exhibit heterogeneous termini. Comparison of the amino acid sequence of the T2 bacteriophage dCMP deaminase with that deduced for the yeast enzyme revealed a limited degree of homology which extends over the entire length of the phage polypeptide (188 amino acids) but is confined to the carboxy-terminal half of the yeast protein (312 amino acids). A potential dTTP-binding site in the yeast and phage enzymes was identified by comparison of homologous regions with the amino acid sequences of a variety of other dTTP-binding enzymes. Despite the role of dCMP deaminase in dTTP biosynthesis, Northern analysis revealed that the DCD1 gene is not subject to the same cell cycle-dependent pattern of transcription recently found for the yeast thymidylate synthetase gene (TMP1).


1993 ◽  
Vol 13 (8) ◽  
pp. 5010-5019 ◽  
Author(s):  
J Heitman ◽  
A Koller ◽  
J Kunz ◽  
R Henriquez ◽  
A Schmidt ◽  
...  

The immunosuppressants cyclosporin A, FK506, and rapamycin inhibit growth of unicellular eukaryotic microorganisms and also block activation of T lymphocytes from multicellular eukaryotes. In vitro, these compounds bind and inhibit two different types of peptidyl-prolyl cis-trans isomerases. Cyclosporin A binds cyclophilins, whereas FK506 and rapamycin bind FK506-binding proteins (FKBPs). Cyclophilins and FKBPs are ubiquitous, abundant, and targeted to multiple cellular compartments, and they may fold proteins in vivo. Previously, a 12-kDa cytoplasmic FKBP was shown to be only one of at least two FK506-sensitive targets in the yeast Saccharomyces cerevisiae. We find that a second FK506-sensitive target is required for amino acid import. Amino acid-auxotrophic yeast strains (trp1 his4 leu2) are FK506 sensitive, whereas prototrophic strains (TRP1 his4 leu2, trp1 HIS4 leu2, and trp1 his4 LEU2) are FK506 resistant. Amino acids added exogenously to the growth medium mitigate FK506 toxicity. FK506 induces GCN4 expression, which is normally induced by amino acid starvation. FK506 inhibits transport of tryptophan, histidine, and leucine into yeast cells. Lastly, several genes encoding proteins involved in amino acid import or biosynthesis confer FK506 resistance. These findings demonstrate that FK506 inhibits amino acid import in yeast cells, most likely by inhibiting amino acid transporters. Amino acid transporters are integral membrane proteins which import extracellular amino acids and constitute a protein family sharing 30 to 35% identity, including eight invariant prolines. Thus, the second FK506-sensitive target in yeast cells may be a proline isomerase that plays a role in folding amino acid transporters during transit through the secretory pathway.


2007 ◽  
Vol 28 (2) ◽  
pp. 551-563 ◽  
Author(s):  
Zhengchang Liu ◽  
Janet Thornton ◽  
Mário Spírek ◽  
Ronald A. Butow

ABSTRACT Cells of the budding yeast Saccharomyces cerevisiae sense extracellular amino acids and activate expression of amino acid permeases through the SPS-sensing pathway, which consists of Ssy1, an amino acid sensor on the plasma membrane, and two downstream factors, Ptr3 and Ssy5. Upon activation of SPS signaling, two transcription factors, Stp1 and Stp2, undergo Ssy5-dependent proteolytic processing that enables their nuclear translocation. Here we show that Ptr3 is a phosphoprotein whose hyperphosphorylation is increased by external amino acids and is dependent on Ssy1 but not on Ssy5. A deletion mutation in GRR1, encoding a component of the SCFGrr1 E3 ubiquitin ligase, blocks amino acid-induced hyperphosphorylation of Ptr3. We found that two casein kinase I (CKI) proteins, Yck1 and Yck2, previously identified as positive regulators of SPS signaling, are required for hyperphosphorylation of Ptr3. Loss- and gain-of-function mutations in PTR3 result in decreased and increased Ptr3 hyperphosporylation, respectively. We found that a defect in PP2A phosphatase activity leads to the hyperphosphorylation of Ptr3 and constitutive activation of SPS signaling. Two-hybrid analysis revealed interactions between the N-terminal signal transduction domain of Ssy1 with Ptr3 and Yck1. Our findings reveal that CKI and PP2A phosphatase play antagonistic roles in SPS sensing by regulating Ptr3 phosphorylation.


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