scholarly journals Optimization of Carotenoids Production from Camelina Sativa Meal Hydrolysate by Rhodosporidium Toruloides

Author(s):  
STEFANO BERTACCHI ◽  
Chiara Cantù ◽  
Danilo Porro ◽  
Paola Branduardi

Abstract BackgroundPetrochemical synthetic dominates several markets, and carotenoids are not an exception. Since their applications in the food, feed and cosmetic sectors, carotenoids of natural origin are increasingly requested, but the production needs to be sustainable also in terms of initial feedstock. For these reasons we deployed the carotenogenic yeast Rhodosporidium toruloides to obtain such compounds from Camelina sativa meal, an underrated lignocellulosic biomass. As the process starts from hydrolyzed biomass, we separately optimized enzymatic and biomass loadings, to reduce the overall process costs. ResultsThe best conditions (9% w/v biomass, 0.56% w/wbiomass enzymes) were tested in different settings, in which fermentation was separate or co-current with the hydrolysis, showing similar carotenoids productions. The process was implemented in stirred-tank bioreactors, obtaining 3.6 ± 0.69 mg/L of carotenoids, and showing to be robust towards changes in different parameters. ConclusionsThese data pave the way to evaluate a possible industrialization of this bioprocess, considering the opportunity to optimize the use of different amounts of biomass and enzyme loading. In addition, the test in bioreactor is an additional step to further develop the proposed process.

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 208
Author(s):  
Stefano Bertacchi ◽  
Chiara Cantù ◽  
Danilo Porro ◽  
Paola Branduardi

Several compounds on the market derive from petrochemical synthesis, and carotenoids are no exception. Nonetheless, since their applications in the food, feed and cosmetic sectors, and because of sustainability issues, carotenoids of natural origin are desirable. Carotenoids can be extracted from several plants but also from carotenogenic microorganisms, among which are yeasts. Nonetheless, to meet sustainability criteria, the substrate used for yeast cultivation has to be formulated from residual biomasses. For these reasons, we deploy the yeast, Rhodosporidium toruloides, to obtain carotenoids from Camelina sativa meal, an underrated lignocellulosic biomass. Its enzymatic hydrolysis ensures the release of the sugars, as well as of the other nutrients necessary to sustain the process. We therefore separately optimized enzymatic and biomass loadings, and calculated the yields and productivities of the obtained carotenoids. The best conditions (9% w/v biomass, 0.56% w/wbiomass enzymes) were tested in different settings, in which the fermentation was performed separately or simultaneously with hydrolysis, resulting in a similar production of carotenoids. In order to collect quantitative data under controlled chemo-physical parameters, the process was implemented in stirred-tank bioreactors, obtaining 3.6 ± 0.69 mg/L of carotenoids; despite the volumetric and geometric change, the outcomes were consistent with results from the fermentation of shake flasks. Therefore, these data pave the way to evaluate a potential future industrialization of this bioprocess, considering the opportunity to optimize the use of different amounts of biomass and enzyme loading, as well as the robustness of the process in the bioreactor.


2019 ◽  
Author(s):  
Stefano Bertacchi ◽  
Maurizio Bettiga ◽  
Danilo Porro ◽  
Paola Branduardi

Abstract Background: The sustainability of biorefineries is strongly related to the origin, the availability and the market of the biomass used as feedstock. Moreover, one of the pillars of circular economy aims at reducing waste, ideally to zero. These considerations well justify the increasing industrial interest in exploiting many and diverse residual biomasses. This work focuses on the valorization of the leftover from Camelina sativa oil extraction, named Camelina meal. Despite Camelina meal is used as animal feed, there is an increasing interest in further valorizing its macromolecular content or its nutritional value. Results: Here we valorized Camelina meal hydrolysates by using them as nutrient and energy source for shake-flask fermentations where Rhodosporidium toruloides , a yeast natural producer of carotenoids, accumulated these pigments as desired product. Initially, by total acid hydrolysis we determined that in Camelina meal carbohydrates account for a maximum of 30.8 ± 1.0 %. However, since the acid hydrolysis is not optimal for subsequent microbial fermentation, an enzymatic hydrolysis protocol was assessed, obtaining a maximum sugar recovery of 53.3%. Having stated that, by Separate Hydrolysis and Fermentation, with or without water insoluble solids (SHF, SHF+WIS), or Simultaneous Saccharification and Fermentation (SSF) we obtained 5.51 ± 0.67, 12.64 ± 2.57, and 15.97 ± 0.67 mg/L of carotenoids, respectively, from Camelina meal hydrolysate. Significantly, the presence of WIS, possibly containing microbial inhibitors, correlates with a higher titer of carotenoids, which can be seen as scavengers. Conclusions: The proposed study paves the way for the development of bioprocesses based on the exploitation of Camelina meal, scarcely investigated in the field before, as feedstock. The processes depicted provide an example of how different final products of industrial interests can be obtained from this leftover, such as pure carotenoids and carotenoid-enriched Camelina meal for the feed industry, without diminishing but possibly increasing its initial value. These data provide valuable basis for the economic evaluations necessary to assess the feasibility of a bioprocess based on Camelina meal to obtain high-value added products.


2017 ◽  
Vol 3 (1) ◽  
pp. 59 ◽  
Author(s):  
Sanjay Mohan Gupta ◽  
Kamal Kumar ◽  
Rakshit Pathak ◽  
Sanjai Kumar Dwivedi

<p>Lignocellulosic biomasses are promising alternative resource for bio-fuel production. But due to the recalcitrant nature of lignin and hemicellulose, necessitates an efficient pre-treatment process to improve the yield of reducing sugars and maximising the enzymatic hydrolysis efficiency. Catalysed-microwave pre-treatment may be a good alternative as compared to other methods since it can reduce the time and improve the enzymatic activity during hydrolysis. The aim of this study was to evaluate the efficiency of the catalysed-microwave based pre-treatment of lignocellulosic biomass of Camelina sativa straw (CSS) to overcome the recalcitrant nature of cellulosic biomass. The microwave-alkaline (2 % NaOH) pre-treatment of CSS at 250 W for 10 min yields maximum (~422 mg/g) total soluble sugars (TSS) production during hydrolysis. Likewise, the maximum glucose content (~294 mg/g) was measured in 2 % alkaline-microwave pre-treatment for 10 min at RT. However, slight increase in lignin degradation was observed with the increase in alkaline hydroxide concentration and microwave irradiation exposure time. The maximum degradation in lignin content (~83 %) was measured in 3 % alkaline-microwave pre-treatment for 20 min at RT. Our results suggest that the microwave-alkaline pre-treatment approach may be employed for comprehensive utilisation of CSS biomass of Camelina sativa L. cv. Calena (EC643910) for bio-fuel production.</p>


Author(s):  
Pooja Gaikwad ◽  
Priyanka Ghumare ◽  
Gayatri Chaudhari ◽  
Sayali Nikam ◽  
Rupali Murtdak ◽  
...  

In this paper, a detailed overview on steganography & its Types, tools, techniques is conducted to study and look over them. This research involves the steganography using binwalk tool in the Necromancer. Necromancer is the vulnerable virtual machine, in order to gain the root access of VM (Virtual Machine) there are 11 flags to collect on the way, Few flags are found by using the Binwalk tool, to know the hint behind image, so we have used an Image steganography in one of flag of Necromancer. Flags are nothing but any encrypted code. Steganography refers to the act of camouflage the secret data within any image, audio, video in order to avoid the detection. The secret data is then extracted at its destination. The use of steganography are often combined with encryption as an additional step for hiding or protecting data.


2020 ◽  
Author(s):  
Vishnu Prasad J. ◽  
Tridweep K. Sahoo ◽  
Naveen S. ◽  
Guhan Jayaraman

Abstract BackgroundSimultaneous saccharification and fermentation (SSF) of pre-treated lignocellulosics to biofuels and other platform chemicals has long been a promising alternative to separate hydrolysis and fermentation processes. However, the disparity between the optimum conditions (temperature, pH) for fermentation and enzyme hydrolysis leads to execution of the SSF process at sub-optimal conditions, which can affect the rate of hydrolysis and cellulose conversion. The fermentation conditions could be synchronized with hydrolysis optima by carrying out the SSF at a higher temperature, but this would require a thermo-tolerant organism. Economically viable production of platform chemicals from lignocellulosic biomass has long been stymied because of the significantly higher cost of hydrolytic enzymes. The major objective of this work is to develop an SSF strategy for D- lactic acid production by a thermo-tolerant organism, in which the enzyme loading could significantly be reduced without compromising on the overall conversion. ResultsA thermo-tolerant strain of Lactobacillus bulgaricuswas developed by adaptive laboratory evolution (ALE) which enabled the SSF to be performed at 45 °C with reduced enzyme usage.Despite the reduction of enzyme loading from 15 FPU/gbiomass to 5 FPU/gbiomass, we could still achieve ~8% higher cellulose to D-LA conversion in batch SSF, in comparison to the conversion by separate enzymatic hydrolysis and fermentation processes at 45 °C and pH 5.5. Extending the batch SSF to an SSF with pulse-feeding of 5% pre-treated biomass and 5 FPU/g-biomass, at12-hour intervals (36th h – 96th h), resulted in a titer of 108 g/L D-LA and 60% conversion of cellulose to D-LA.This is one among the highest reported D-LA titers achieved from lignocellulosic biomass.ConclusionsWe have demonstrated that the SSF strategy, in conjunction with evolutionary engineering, could drastically reduce enzyme requirement and be the way forward for economical production of platform chemicals from lignocellulosics. We have shown that fed-batch SSF processes, designed with multiple pulse-feedings of the pre-treated biomass and enzyme, can be an effective way of enhancing the product concentrations.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jessica C. Rohrbach ◽  
Jeremy S. Luterbacher

Abstract Background Understanding how the digestibility of lignocellulosic biomass is affected by its morphology is essential to design efficient processes for biomass deconstruction. In this study, we used a model based on a set of partial differential equations describing the evolution of the substrate morphology to investigate the interplay between experimental conditions and the physical characteristics of biomass particles as the reaction proceeds. Our model carefully considers the overall quantity of cellulase present in the hydrolysis mixture and explores its interplay with the available accessible cellulose surface. Results Exploring the effect of various experimental and structural parameters highlighted the significant role of internal mass transfer as the substrate size increases and/or the enzyme loading decreases. In such cases, diffusion of cellulases to the available cellulose surface limits the rate of glucose release. We notably see that increasing biomass loading, while keeping enzyme loading constant should be favored for both small- (R < 300 $$\mu m$$ μ m ) and middle-ranged (300 < R < 1000 $$\mu m$$ μ m ) substrates to enhance enzyme diffusion while minimizing the use of enzymes. In such cases, working at enzyme loadings exceeding the full coverage of the cellulose surface (i.e. eI>1) does not bring a significant benefit. For larger particles (R > 1000 $$\mu m$$ μ m ), increases in biomass loading do not offset the significant internal mass transfer limitations, but high enzyme loadings improve enzyme penetration by maintaining a high concentration gradient within the particle. We also confirm the well-known importance of cellulose accessibility, which increases with pretreatment. Conclusions Based on the developed model, we are able to propose several design criteria for deconstruction process. Importantly, we highlight the crucial role of adjusting the enzyme and biomass loading to the wood particle size and accessible cellulose surface to maintain a strong concentration gradient, while avoiding unnecessary excess in cellulase loading. Theory-based approaches that explicitly consider the entire lignocellulose particle structure can be used to clearly identify the relative importance of bottlenecks during the biomass deconstruction process, and serve as a framework to build on more detailed cellulase mechanisms.


2017 ◽  
Vol 64 ◽  
pp. 96-106 ◽  
Author(s):  
Pavel Svehla ◽  
Helena Radechovska ◽  
Lukas Pacek ◽  
Pavel Michal ◽  
Ales Hanc ◽  
...  

2017 ◽  
Vol 79 (4) ◽  
Author(s):  
Siti Norbaidurah Ayob ◽  
Abdul Munir Abdul Murad ◽  
Farah Diba Abu Bakar ◽  
Rosli Md Illias

There are abundant of lignocellulosic biomass readily available with varying compositions. Kenaf (Hibiscus cannabinus) is one of this lignocellulosic biomass that has a high content of hemicellulose. This particular hemicellulose is composed of high arabinoxylan, which is a xylan backbone with arabinofuranosyl branches. In order to hydrolyze arabinoxylan, a branching enzyme is needed. Therefore, α-L-arabinofuranosidase from Aspergillus niger ATCC120120 (AnabfA) was used to hydrolyzed pre-treated kenaf and the reaction conditions were optimized using central composite design (CCD) to produce a significant amount of arabinose. There were 20 experiments conducted with 1.68 star points and 6 replicates at the centre points. The reaction conditions that were optimized are enzyme loading, substrate concentration and reaction time in which resulted with 88 U AnabfA activity, 0.9% (w/v) and 48 h, respectively. These optimized conditions managed to increase the yield of arabinose with 47.17 mg/g arabinose produced. 


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