35 research outputs found
Production of Lovastatin, (+)-Geodin and Sulochrin by Aspergillus Terreus ATCC 20542 using Pure and Crude Glycerol
This study aimed to characterise the production of lovastatin and its co-metabolites, sulochrin and (+)-geodin by A. terreus. Firstly, the study revealed that the types of carbon source influence lovastatin production, whilst the types of nitrogen source influence (+)-geodin and sulochrin production. Glycerol and yeast extract culture produced reasonable amount of lovastatin (25.68 mg/L), (+)-geodin (9.00 mg/L) and sulochrin (22.35 mg/L). This culture also produced pellets with hairy morphology, which is optimal for metabolite production. Secondly, the potential of crude glycerol (CG) as the substrate for A. terreus cultivation was investigated. At 30 g/L CG, (+)-geodin (13.14 mg/L) and sulochrin (14.79 mg/L) increased ~2-fold, but lovastatin production decreased by ~35%. The presence of saturated fatty acids (~48% reduction) and soap (~90% reduction) contributed to the inhibitory effect of CG on lovastatin production, with no effects on (+)-geodin and sulochrin production. Partial purification of CG using solvent and activated carbon resulted in an improved yield of all three metabolites. Thirdly, this study investigated the effects of selected ‘elicitors’ on the production of metabolites. Chemical elicitor was found to stimulate the production of lovastatin and sulochrin. (+)-geodin’s production was suppressed in high viscosity condition (500 mg/L). These observations indicate that lovastatin and sulochrin may play a role in A. terreus’ defense mechanism. (+)-geodin, however, may be important for fungal pellet integrity or immediate response to injury, as physical elicition greatly enhanced its production. In conclusion, CG is a promising alternative substrate for metabolite production by A. terreus. This study, however, demonstrates no apparent relationship between the production of lovastatin, (+)-geodin and sulochrin by A. terreus
Production of Lovastatin, (+)-Geodin and Sulochrin by Aspergillus Terreus ATCC 20542 using Pure and Crude Glycerol
This study aimed to characterise the production of lovastatin and its co-metabolites, sulochrin and (+)-geodin by A. terreus. Firstly, the study revealed that the types of carbon source influence lovastatin production, whilst the types of nitrogen source influence (+)-geodin and sulochrin production. Glycerol and yeast extract culture produced reasonable amount of lovastatin (25.68 mg/L), (+)-geodin (9.00 mg/L) and sulochrin (22.35 mg/L). This culture also produced pellets with hairy morphology, which is optimal for metabolite production. Secondly, the potential of crude glycerol (CG) as the substrate for A. terreus cultivation was investigated. At 30 g/L CG, (+)-geodin (13.14 mg/L) and sulochrin (14.79 mg/L) increased ~2-fold, but lovastatin production decreased by ~35%. The presence of saturated fatty acids (~48% reduction) and soap (~90% reduction) contributed to the inhibitory effect of CG on lovastatin production, with no effects on (+)-geodin and sulochrin production. Partial purification of CG using solvent and activated carbon resulted in an improved yield of all three metabolites. Thirdly, this study investigated the effects of selected ‘elicitors’ on the production of metabolites. Chemical elicitor was found to stimulate the production of lovastatin and sulochrin. (+)-geodin’s production was suppressed in high viscosity condition (500 mg/L). These observations indicate that lovastatin and sulochrin may play a role in A. terreus’ defense mechanism. (+)-geodin, however, may be important for fungal pellet integrity or immediate response to injury, as physical elicition greatly enhanced its production. In conclusion, CG is a promising alternative substrate for metabolite production by A. terreus. This study, however, demonstrates no apparent relationship between the production of lovastatin, (+)-geodin and sulochrin by A. terreus
Nondestructive testing using ultrasonic sensor
Nondestructive testing (NDT) is the process of inspection or evaluating materials or component without destroying the functionality, serviceability and the structure of the testing product. Therefore, after the inspection is done the testing product can still be used as usual compared to the destructive testing that can cause the damage to the testing product. In the other word destructive testing has limitation because of the technique need a sampling product rather than on the materials is already put into the service. NDT are often used to determine the properties of the materials such as strengthen ductility, porosity and toughness. Todays, NDT are widely used in industries, manufacturing, and fabrication and in service inspection to ensure the quality of the product. Besides that, NDT also can reduce production cost by minimize the damage onto the product and also can reduce the production time by without damaging the testing product. Also in construction field, there are many benefits from NDT process toward this area such as to evaluate the strength of concrete. There are many method of NDT today such as Magnetic Particle Testing, Ultrasonic Testing, and Vibration Analysis. For testing of the building basically people are used the Ultrasonic Pulse Velocity (UPV) and Rebound Hammer. This paper is specifically discussed about the Nondestructive Testing (NDT) by using Ultrasonic
Effects of different preservation treatments on nutritional profile on juices from different sugar cane varieties
The commercialisation of sugarcane juice is limited due to its rapid quality degradation. This study was conducted to determine the effect of High Pressure Processing (HPP) and High Pressure Homogenisation (HPH) on physicochemical, antioxidant properties and microbiological quality of red sugarcane juice. The red sugarcane juice samples, Kapur, Madu, Serai and Ragnar were subjected to HPP and HPH at 300 MPa for 2 and 5 min before the analysis was performed. Initial brix content, polyphenol oxidase (PPO) and nutritional content of sugarcane juice values of showed that Madu juice contained the highest total phenolic content (TPC) and antioxidant properties (FRAP and DPPH radical scavenging assay) amongst all variants. HPP-treated juice showed no significant difference to the untreated juice in terms of physicochemical properties (total soluble solid, pH and colour), microbial count and polyphenoloxidase activity. In contrast, HPH showed significant decrease in microbial load and polyphenoloxidase activity. The sugar cane juice subjected to HPP and HPH for 5 min showed significant increase and significant decrease, respectively, in term of TPC as compared to untreated sample. In conclusion, HPP appears to be an effective approach to retain TSS, pH and colour of the red sugarcane juice, while increasing the antioxidant quantity which is desirable in the commercialisation of the juice. However, HPH is a better method to reduce PPO activity and microbial load, thus beneficial in reducing the browning process and potentially extending the shelf life
Improved lovastatin production by inhibiting (+)-geodin biosynthesis in aspergillus terreus
Lovastatin is widely prescribed to reduce elevated levels of cholesterol and prevent heart-related diseases. Cultivation of Aspergillus terreus (ATCC 20542) with carbohydrates or low-value feedstocks such as glycerol produces lovastatin as a secondary metabolite and (+)-geodin as a by-product. An A. terreus mutant strain was developed (gedCΔ) with a disrupted (+)-geodin biosynthesis pathway. The gedCΔ mutant was created by inserting the antibiotic marker hygromycin B (hyg) within the gedC gene that encodes emodin anthrone polyketide synthase (PKS), a primary gene responsible for initiating (+)-geodin biosynthesis. The effects of emodin anthrone PKS gene disruption on (+)-geodin and lovastatin biosynthesis and the production of the precursors acetyl-CoA and malonyl-CoA were investigated with cultures based on glycerol alone and in combination with lactose. The gedCΔ strain showed improved lovastatin production, particularly when cultivated on the glycerol-lactose mixture, increasing lovastatin production by 80% (113 mg/L) while simultaneously inhibiting (+)-geodin biosynthesis compared to the wild-type strain. This study thus shows that suppression of the (+)-geodin pathway increases lovastatin yield and demonstrates a practical approach of manipulating carbon flux by modulating enzyme activity
Pretreatment strategies to improve crude glycerol utilisation and metabolite production by Aspergillus terreus
Crude glycerol (CG) can be used as a substrate for microbial bioconversion. However, due to presence of many impurities, manymicroorganisms are unable to utilise this substrate efficiently. +e present study is trying to improve CG using as the feedstock ofAspergillusterreusfor the production of lovastatin, (+)-geodin, and sulochrin. +e CG was pretreated chemically (solvents) andphysically (activated carbon (AC) and water softener (WS)) to separate most of the impurities from the CG. For solventpretreatments, petroleum ether (PE) produced the largest increase of lovastatin (92.8%) when compared to positive control andpure glycerol (PG) and up to 820% when compared to negative control (CG). In contrast, diethyl ether (DE) produced the largestincrease in (+)-geodin at 80.81% (versus CG) and 176.23% (versus PG). +e largest increase in toluene (Tol) was observed insulochrin production, at 67.22% (versus CG) and 183.85% (versus PG). For physical pretreatments, the pattern of metaboliteproduction in AC (lovastatin: 20.65 mg/L, (+)-geodin: 7.42 mg/L, sulochrin: 11.74 mg/L) resembled PG (lovastatin: 21.8 mg/L,(+)-geodin: 8.60 mg/L, sulochrin: 8.18 mg/L), while WS (lovastatin: 11.25 mg/L, (+)-geodin: 15.38 mg/L, sulochrin: 16.85 mg/L)resembled CG (lovastatin: 7.1 mg/L, (+)-geodin:17.10 mg/L, sulochrin:14.78 mg/L) at day 6 of fermentation. +ese results indicatethat solvent pretreatments on CG are excellent for metabolites production inA. terreus, depending on the solvents used. Incontrast, physical pretreatments are only feasible for (+)-geodin and sulochrin production. +erefore, different strategies can beemployed to manipulate theA. terreusbioconversion using improved CG by using a few simple pretreatment strategies
The effect of viscosity, friction, and sonication on the morphology and metabolite production from Aspergillus terreus ATCC 20542
This study investigates the effects of viscosity, friction, and sonication on the morphology and the production of lovastatin, (+)-geodin, and sulochrin by Aspergillus terreus ATCC 20542. Sodium alginate and gelatine were used to protect the fungal pellet from mechanical force by increasing the media viscosity. Sodium alginate stimulated the production of lovastatin by up to 329.0% and sulochrin by 128.7%, with inhibitory effect on (+)-geodin production at all concentrations used. However, the use of gelatine to increase viscosity significantly suppressed lovastatin, (+)-geodin, and sulochrin’s production (maximum reduction at day 9 of 42.7, 60.8, and 68.3%, respectively), which indicated that the types of chemical play a major role in metabolite production. Higher viscosity increased both pellet biomass and size in all conditions. Friction significantly increased (+)-geodin’s titre by 1527.5%, lovastatin by 511.1%, and sulochrin by 784.4% while reducing pellet biomass and size. Conversely, sonication produced disperse filamentous morphology with significantly lower metabolites. Sodium alginate-induced lovastatin and sulochrin production suggest that these metabolites are not affected by viscosity; rather, their production is affected by the specific action of certain chemicals. In contrast, low viscosity adversely affected (+)-geodin’s production, while pellet disintegration can cause a significant production of (+)-geodin
The investigation of media components for optimal metabolite production of Aspergillus terreus ATCC 20542
Purpose: This study aimed to assess the effect of nitrogen, salt and pre-culture conditions on the production of lovastatin in A. terreus ATCC 20542. Methods: Different combinations of nitrogen sources, salts and pre-culture combinations were applied in the fermentation media and lovastatin yield was analysed chromatographically. Result: The exclusion of MnSO₄ ·5H₂O, CuSO₄·5H₂O and FeCl₃·6H₂O were shown to significantly improve lovastatin production (282%), while KH2PO₄, MgSO₄·7H₂O, and NaCl and ZnSO4·7H₂O were indispensable for good lovastatin production. Simple nitrogen source (ammonia) was unfavourable for morphology, growth and lovastatin production. In contrast, yeast extract (complex nitrogen source) produced the highest lovastatin yield (25.52 mg/L), while powdered soybean favoured the production of co-metabolites ((+)-geodin and sulochrin). Intermediate lactose: yeast extract (5:4) ratio produced the optimal lovastatin yield (12.33 mg/L) during pre-culture, while high (5:2) or low (5:6) lactose to yeast extract ratio produced significantly lower lovastatin yield (7.98 mg/L and 9.12 mg/L, respectively). High spore concentration, up to 107 spores/L was shown to be beneficial for lovastatin, but not for co-metabolite production, while higher spore age was shown to be beneficial for all of its metabolites. Conclusion: The findings from these investigations could be used for future cultivation of A. terreus in the production of desired metabolites
Growth and lovastatin production by Aspergillus terreus under different carbohyrates as carbon sources
Carbon source is a key component of metabolites synthesis in microorganisms. This work examined the effects of selected carbon sources in the form of carbohydrates, on the growth of Aspergillus terreus ATCC 20542 and the production of lovastatin. Slowly metabolised carbohydrates, such as D-galactose (consumption rate, r=3.11), produced a high microbial biomass, XFINAL (9.44 g/L) compared to other carbohydrates, but with a low biomass yield coefficient (YLOV/X=1.68). In contrast, D-ribose (YLOV/X=) which showed moderate biomass growth (XFINAL=8.78 g/L) and consumption rate (r=5.44 g/day), produced the highest lovastatin amount (51.81 mg/L, day 6). These indicate little correlation between biomass growth and lovastatin production. Notably, culture consisting of pellets with short hairy surface feature is associated with enhanced lovastatin production. Our findings suggest that the production of lovastatin by Aspergillus terreus is highly influenced by the choice of carbohydrates that will shape the pellet morphology rather than the rate of carbohydrates metabolism
Comparative analysis on the Role of 2,4-dichlorophenoxyacetic acid in the expression of bioactive compounds in callus of capsicum frutescens
Plant cell culture technology serves as an effective alternative system for in vitro production of bioactive molecules, as
it allows for the exploration of valuable compounds under a controlled environment. The present study was conducted
to evaluate the effect of plant growth regulator (PGR); 2,4-dichlorophenoxyacetic acid (2,4-D) on the expression of
compounds in coloured callus of Capsicum frutescens, a vital spice in various cuisines worldwide. The differential
accumulation of compounds in the callus was analysed using liquid chromatography-mass spectrometry (LCMS) and
the PGR concentration that resulted in the highest accumulation of the valuable compounds was identified. In this
study, calli of various colours (cream, yellow and green) were successfully produced from C. frutescens through
plant tissue culture. The increase in 2,4-D concentrations was found to increase callus growth index (GI) and specific
growth rate (Sg
), where the highest GI (0.5690) and Sg
(0.6348 mg/week) were observed in callus produced in media
supplemented with 0.5 mg/L 2,4-D. LCMS data analyses showed that 19 compounds were detected in the callus, with 8
compounds (fatty acids and phenolics) were successfully identified, while the remaining 11 compounds were reported
as unknowns. Yellow-coloured callus was observed to contain the highest number of compounds (18 compounds),
while green callus contained the least (14 compounds). This analysis provides valuable information on the application
of biotechnological tools such as plant tissue culture as an alternative for sustainable production of compounds with
high bioactivity in Capsicum frutescens