Due to increasing demands for microalgal biomass and products originating from microalgae, large-scale production systems are necessary. However, current microalgal production technologies are not ...cost-effective and are hindered by various bottlenecks, one of which is the harvesting of microalgal biomass. Cell separation is difficult because of the low sedimentation velocity of microalgae, their colloidal character with repelling negative surface charges, and low biomass concentrations in culture broths; therefore, large volumes need to be processed in order to concentrate the cells. Flocculation is considered to be one of the most suitable methods for harvesting microalgal biomass. This article provides an overview of flocculation methods suitable for microalgal harvesting, their mechanisms, advantages and drawbacks. Special attention is paid to the role of surface charge in the mechanism of flocculation. The novelty of the review lies in the interconnection between the context of technological applications and physico-chemical surface phenomena.
Due to their bioavailability, glycosylated carotenoids may have interesting biological effects. Sioxanthin, as a representative of this type of carotenoid, has been identified in marine actinomycetes ...of the genus
. This study evaluates, for the first time, the effect of cultivation temperature (T) and light intensity (LI) on the total cellular carotenoid content (TC), antioxidant activity (AA) and sioxanthin content (SX) of a crude extract (CE) from
biomass in its vegetative state. Treatment-related differences in TC and SX values were statistically significantly and positively affected by T and LI, while AA was most significantly affected by T. In the
CE, TC correlated well (R
= 0.823) with SX and somewhat less with AA (R
= 0.777). A correlation between AA and SX was found to be less significant (R
= 0.731). The most significant protective effect against oxidative stress was identified in the CE extracted from
biomass grown at the highest T and LI (CE-C), as was demonstrated using LNCaP and KYSE-30 human cell lines. The CE showed no cytotoxicity against LNCaP and KYSE-30 cell lines.
Objective
Marine actinomycetes from the genus
Salinispora
have an unexploited biotechnological potential. To accurately estimate their application potential however, data on their cultivation, ...including biomass growth kinetics, are needed but only incomplete information is currently available.
Results
This work provides some insight into the effect of temperature, salinity, nitrogen source, glucose concentration and oxygen supply on growth rate, biomass productivity and yield of
Salinispora tropica
CBN-440
T
. The experiments were carried out in unbaffled shake flasks and agitated laboratory-scale bioreactors. The results show that the optimum growth temperature lies within the range 28–30 °C, salinity is close to sea water and the initial glucose concentration is around 10 g/L. Among tested nitrogen sources, yeast extract and soy peptone proved to be the most suitable. The change from unbaffled to baffled flasks increased the volumetric oxygen transfer coefficient (k
L
a) as did the use of agitated bioreactors. The highest specific growth rate (0.0986 h
−1
) and biomass productivity (1.11 g/L/day) were obtained at k
L
a = 28.3 h
−1
. A further increase in k
L
a was achieved by increasing stirrer speed, but this led to a deterioration in kinetic parameters.
Conclusions
Improvement of
S. tropica
biomass growth kinetics of was achieved mainly by identifying the most suitable nitrogen sources and optimizing k
L
a in baffled flasks and agitated bioreactors.
This paper explores the use of the passive in present-day British English, focusing on its register-specific lexico-grammatical patterns. The interaction of the grammatical structure, lexis, ...phraseology and register is examined on the basis of two sub-corpora of the
– academic prose and informal conversation. The results have corroborated the findings of previous studies in that the pattern
is populated by verbal participial forms which create a cline with departicipial adjectives. The communicative needs of registers have been shown to have a decisive impact on the frequency of passive patterns and the specific lexical choices associated with the patterns. In both registers, the
patterns appear to constitute the core of larger fixed phraseological units, e.g.,
or
The medfly (Ceratitis capitata) is one of the major agricultural pests controlled through sterile insect technique (SIT) programs. We studied the chemical composition of the volatiles released by ...calling males from one laboratory and two wild C. capitata populations using two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC × GC/TOFMS) and gas chromatography with electroantennographic detection (GC-EAD). Multivariate data analyses revealed significant differences in the quantitative and qualitative composition of male chemical emanations between the three populations. The GC-EAD analyses of the male emanation of three C. capitata populations revealed 14 antenally active compounds. The volatiles isomenthone, β-pinene, ethyl octanoate, indole, geraniol, bornyl acetate, geranyl acetone, and (E)-caryophyllene are newly reported EAD active constituents of the male pheromone. GC-EAD analyses of the laboratory population indicated that the males and females of C. capitata possess comparable sensitivity to male-produced volatiles. Our results are relevant to the development of a pheromone-based monitoring system and also to the SIT control program.
Saline waste water from demineralization of cheese whey was used as the main component of waste saline medium (WSM) for cultivation of thraustochytrids. The suitability of WSM for cultivation of
...Schizochytrium limacinum
PA-968 and
Japonochytrium marinum
AN-4 was evaluated by comparison with cultivation on nutrient medium (NM) in shake flask and fermenter cultures. Biomass productivities achieved in WSM for the thraustochytrids were comparable with those in NM for both shake flask and fermenter cultures. The maximum total lipid content (56.71% dry cell weight) and docosahexaenoic acid productivity (0.86 g/L/day) were achieved by
J. marinum
AN-4 grown on WSM in shake flask and fermenter cultures, respectively. A cost estimate of WSM suggests that this medium could result in lower production costs for thraustochytrid biomass and lipids and contribute to the effective reduction in saline diary process waste water.
Comprehensive evaluation of performance analysis of PBS INDUSTRY, a.s. When evaluating the performance of PBS INDUSTRY, a.s. the financial statements of the company for the period of 2005 -- 2008 are ...used. Performance evaluation is done through traditional methods of financial analysis and modern methods of economic added value. The interpretation of analytical results and recommendations was made.
The Ceratitis capitata is a very important agricultural pest, whose reproduction behaviour is controled by chemical signals. Males initiate mating by creating leks, where they release sexual ...pheromones to attract females. The main goal of this diploma thesis was to determine the influence of host plants on the composition of male sex-pheromones C. capitata and to compare emanations of wild males with those originating from laboratory population. We studied the chemical composition of volatiles, released by calling males C. capitata from laboratory and two wild populations, using two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC-TOFMS), gas chromatography with electroantennographic and flame ionization detection (GC-EAD-FID). All data were statistically analyzed by multivariate data analyses. Significant differences were observed in the quantitative and qualitative composition of the chemical emanations among males from the three populations. The GC-EAD-FID analyses revealed fourteen antenally active compounds with a possible behavioral function. Isomenthone, geraniol, bornyl acetate, geranyl acetone and ethyl octanoate were newly identified antenally active compounds of C. capitata male sex pheromone. Statistical analyses indicated that males and females of...
This paper deals with the determination of the intrinsic value of the company Seznam.cz, a.s. using discounted cash flow. Specifically, it is concerned with determining the value of the business from ...the perspective of the company’s shareholders. The Free Cash Flow to Equity (FCFE) method is chosen for analysis and determination of the value. According to this method, the specific FCFE values are discovered. However, the enterprise value must also be analyzed on the basis of other key indicators, such as financial leverage, the Capital Asset Pricing Model (CAPM) method, or the net present and future value of the FCFE. This is especially important so that the results can be put into mutual relations and a sufficient representative value of the FCFE results can be achieved. Input values stem from the company’s annual reports. From the results of the mentioned methods and indicators, it was found that the value of the FCFE is quite high, which means that the capital used is used appropriately. Based on the result of the continuing value of the FCFE, it can be said that the company’s intrinsic value is at a very good level.
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