scholarly journals EXPERIMENTAL DESIGN FOR SIMULTANEOUS PRODUCTION OF PHB, MESOPHILIC PROTEASES AND LIPASES

2011 ◽  
Vol 12 (2) ◽  
pp. 155-184 ◽  
Author(s):  
Amro Abd al fattah Amara

ABSTRACT: Bacillus species are able to produce PHB, Proteases and Lipases. Bacillus subtilius, Bacillus pumilus, Bacillus therigienesis and Bacillus sp. were used. Plackett-Burman, Box-Behnken design and the Excel solver were used to optimize the production. The statistical analysis of the results proved insignificant relationship between the media compositions and the responses. The results clearly proved a competition between the production of PHB, Proteases and Lipases. Meanwhile systematic experimental design succeeded to minimize this competition. The maximum gained PHB in this study were 16.48 g/l/48 hr. In case of Proteases and Lipases were 534, and 22.56 Units/ml/48 h respectively. The strategies used in this study are recommended for simultaneous production of PHB and proteases. For some extend lipases produced too.

2013 ◽  
Vol 14 (1) ◽  
Author(s):  
Amro Abd al fattah Amara

Mixed culture is more suitable to adapt more flexible fermentation process and produce different product simultaneously. In this study a mixed Bacillus culture was investigated for their ability to produce the bioplastic "Polyhydroxybutyrate" and both of the mesophilic and the thermophilic proteases in one flask. Box-Behnken experimental design was used. The produced amount of PHB has been increased significantly. Meanwhile there is a competition between PHB and proteases. The maximum produced amount of PHB using Box-Behnken design was 2.82 g/l/48 h with protease activity equal to 41.9 Units/ml/48 h for thermophilic proteases and 99.65 Units/ml/48 h for mesophilic proteases. Excel solver was used for extra-optimization for the optimum conditions obtained from Box-Behnken experiments and its model. The maximum PHB obtained after using Excel solver was 2.88 g/l/48 h. The maximum mesophilic and thermophilic activities obtained at the same PHB production conditions were 175.68 and 243.38 Units/ml respectively. The model accuracy as obtained from Excel solver was 118.8%, which prove the power of the experimental design in optimizing such complicated process. The strategies used in this study are recommended for the production of PHB and different proteases simultaneously using Bacillus mixed culture. ABSTRAK: Kultur campuran adalah lebih sesuai bagi proses penapaian yang fleksibel dan ia boleh menghasilkan produk yang berbeza secara serentak. Dalam kajian ini keupayaan  menghasilkan "Polyhydroxybutyrate" bioplastik serta mesofilik dan termofilik protease dalam satu flask oleh  kultur Bacillus campuran telah disiasat. Eksperimen rekabentuk Box-Behnken telah digunakan. Jumlah PHB yang dikeluarkan meningkat dengan ketara dan terdapat persaingan antara PHB dan protease. Jumlah keluaran PHB maksima menggunakan rekabentuk Box-Behnken adalah 2.82 g/l/48 jam dengan aktiviti protease sama dengan 41.9 Unit/ml/48 jam untuk protease termofilik dan 99.65 Unit/ml/48 h untuk protease mesofilik. Solver Excel telah digunakan untuk memperolehi kadar optimum tambahan dari keadaan optimum yang diperolehi dari experimen dan model Box-Behnken. PHB maksimum diperolehi setelah menggunakan solver Excel adalah 2.88 g/l/48 jam. Aktiviti mesofilik dan termofilik maksima diperolehi daripada keadaan pengeluaran PHB yang sama adalah 175.68 dan 243.38 Unit / ml. Ketepatan model diperolehi daripada solver Excel adalah 118.8%, membuktikan kekuatan eksperimen tersebut bagi mengoptimumkan proses yang rumit. Strategi yang digunakan dalam kajian ini adalah disyorkan bagi pengeluaran PHB dan proteas berbeza secara serentak menggunakan kultur Bacillus campuran.KEYWORDS: PHB; proteases; mixed culture; Box-Behnken design.


2019 ◽  
Author(s):  
Yasin Orooji ◽  
Fatemeh Noorisafa ◽  
Nahid Imami ◽  
Amir R. Chaharmahali

<p>Using experimental design and statistical analysis (½ Fractional Factorial Design), this study investigates the effect of different parameters in the membrane fabrication on the performance of nanocomposite PES/TiO<sub>2</sub> membrane. </p>


2019 ◽  
Vol 17 ◽  
Author(s):  
Farzane Kargar ◽  
Mojtaba Mortazavi ◽  
Mahmood Maleki ◽  
Masoud Torkzadeh Mahani ◽  
Younes Ghasemi ◽  
...  

Aims: The purpose of this study was to screen the bacteria producing cellulase enzymes and their bioinformatics studies. Background: Cellulose is a long-chain polymer of glucose that hydrolyzes by cellulases to glucose molecules. In order to design the new biotechnological applications, some strategies have been used as increasing the efficiency of enzyme production, generating cost-effective enzymes, producing stable enzymes and identification of new strains. Objective: On the other hand, some bacteria special features have made them suitable candidates for the identification of the new source of enzymes. In this regard, some native strains of bacteria were screened. Method: These bacteria were grown on a culture containing the liquid M9 media containing CMC to ensure the synthesis of cellulase. The formation of a clear area in the culture medium indicated decomposition of cellulose. In the following, the DNA of these bacteria were extracted and their 16S rDNA genes were amplified. Result: The results show that nine samples were able to synthesize cellulase. In following, these strains were identified using 16S rDNA. The results show that these screened bacteria belonged to the Bacillus sp., Alcaligenes sp., Alcaligenes sp., and Enterobacter sp.conclusionThe enzyme activity analysis shows that the Bacillus toyonensis, Bacillus sp. strain XA15-411 Bacillus cereus have produced the maximum yield of cellulases. However, these amounts of enzyme production in these samples are not proportional to their growth rate. As the bacterial growth chart within 4 consecutive days shows that the Alcaligenes sp. Bacillus cereus, Bacillus toyonensis, Bacillus sp. strain XA15-411 have a maximum growth rate. The study of the phylogenetic tree also shows that Bacillus species are more abundant in the production of cellulase enzyme. These bioinformatics analyses show that the Bacillus species have different evolutionary relationships and evolved in different evolutionary time. Other: However, for maximum cellulase production by this bacteria, some information as optimum temperature, optimum pH, carbon and nitrogen sources are needed for the ideal formulation of media composition. The cellulase production is closely controlled in microorganisms and the cellulase yields appear to depend on a variety of factors. However, the further studies are needed for cloning, purification and application of these new microbial cellulases in the different commercial fields as in food, detergent, and pharmaceutical, paper, textile industries and also various chemical industries. However, these novel enzymes can be further engineered through rational design or using random mutagenesis techniques.


2007 ◽  
Vol 64 (3) ◽  
pp. 308-313 ◽  
Author(s):  
Eniel David Cruz ◽  
José Edmar Urano de Carvalho ◽  
Rafaela Josemara Barbosa Queiroz

Seed coat impermeability to water occurs in many species, including Schizolobium amazonicum Huber ex Ducke. To promote germination in seeds with coat impermeability the use of sulphuric acid (H2SO4) is recommended. The objective of this study was to identify a better time for the scarification with sulphuric acid for S. amazonicum seeds. The effect of scarification with sulphuric acid for 20, 40 and 60 min on germination and speed germination was studied for seeds that were either sowed immediately after scarification or after a 24-hour period of immersion in water. Seeds were sown on a mix of sand and sawdust (1:1). The experimental design was completely randomized with four replications of 50 seeds. The statistical analysis of germination was carried out at six, nine, 12, 15, 18, 21 and 24 days after sowing, in a factorial scheme. For speed germination the means were compared by the Tukey test. There was an interaction between treatments to overcome dormancy and immersion time after scarification in most evaluations. Immersion in water accelerated the beginning of germination. All treatments to overcome dormancy promoted seed germination. However, scarification for 60 min, showed better germination, 92% when immediately sown and 86.5% when sown after 24 hours. Speed germination index was highest for scarified seeds for 60 min followed by immersion in water. Scarification for 60 min was the most efficient treatment to promote germination in S. amazonicum seeds.


2020 ◽  
Vol 1 (1) ◽  
pp. 1-5
Author(s):  
Siwi Puji Astuti ◽  
Alhidayatuddiniyah TW ◽  
Santy Handayani

Learning media is a communication tool both print and audiovisual that is used to convey the material that will be delivered by educators to students in the learning process. The use of media as learning should receive special attention from educators in each learning process. If the media as a learning tool used is very interesting, it does not rule out the possibility that students will better understand the concepts that will be delivered in the learning process to the fullest. Media that can be used in learning physics one of which is Crocodile Physics. This research was conducted to determine the positive effect of using Crocodile Physics media in learning on understanding physics concepts. The study was conducted at Indraprasta PGRI University in 2018. The population is the first semester students of the 2018/2019 academic year. The researcher used quantitative research methods. The experimental design used is classical experimental design. The data analysis technique used is the Independent sample t-test using the SPSS 16 program. The research hypothesis to be tested is that there is a positive influence on the use of Crocodile Physics media in learning to understand physics concepts. The results of the calculation of the study have a sig value of 0.00 < 0.05 which states that there is a positive influence on the use of Crocodile Physics media in learning towards understanding physics concepts. Therefore the results of the study state that there is a positive influence on the use of Crocodile Physics media in learning towards understanding physics concepts.


2020 ◽  
pp. 002367722090761 ◽  
Author(s):  
Florian Frommlet ◽  
Georg Heinze

The recent discussion on the reproducibility of scientific results is particularly relevant for preclinical research with animal models. Within certain areas of preclinical research, there exists the tradition of repeating an experiment at least twice to demonstrate replicability. If the results of the first two experiments do not agree, then the experiment might be repeated a third time. Sometimes data of one representative experiment are shown; sometimes data from different experiments are pooled. However, there are hardly any guidelines about how to plan for such an experimental design or how to report the results obtained. This article provides a thorough statistical analysis of pre-planned experimental replications as they are currently often applied in practice and gives some recommendations about how to improve on study design and statistical analysis.


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