Parasites are now known to be ubiquitous across biological systems and can play an important role in modulating algal populations. However, there is a lack of extensive information on their role in ...artificial ecosystems such as algal production ponds and photobioreactors. Parasites have been implicated in the demise of algal blooms. Because individual mass culture systems often tend to be unialgal and a select few algal species are in wide scale application, there is an increased potential for parasites to have a devastating effect on commercial scale monoculture. As commercial algal production continues to expand with a widening variety of applications, including biofuel, food and pharmaceuticals, the parasites associated with algae will become of greater interest and potential economic impact. A number of important algal parasites have been identified in algal mass culture systems in the last few years and this number is sure to grow as the number of commercial algae ventures increases. Here, we review the research that has identified and characterized parasites infecting mass cultivated algae, the techniques being proposed and or developed to control them, and the potential impact of parasites on the future of the algal biomass industry.
•Inherent resilience and its drivers are spatially variable.•The Midwest and Northeast have higher levels of inherent resilience than elsewhere in the US.•Lowest levels of resilience are in Texas ...border counties, Appalachia, and the interior western US.•Resilience and vulnerability are statistically related, but not the obverse of one another.
There is increasing policy and research interest in disaster resilience, yet the extant literature is still mired in definitional debates, epistemological orientations of researchers, and differences in basic approaches to measurement. As a consequence, there is little integration across domains and disciplines on community resilience assessment, its driving forces, and geographic variability. Using US counties as the study unit, this paper creates an empirically-based resilience metric called the Baseline Resilience Indicators for Communities (BRIC) that is both conceptually and theoretically sound, yet, easy enough to compute for use in a policy context. A common set of variables were used to measure the inherent resilience of counties in the United States according to six different domains or capitals as identified in the extant literature – social, economic, housing and infrastructure, institutional, community, and environmental. Data were from public and freely accessible data sources. Counties in the US Midwest and Great Plains states have the most inherent resilience, while counties in the west, along the US-Mexico border, and along the Appalachian ridge in the east contain the least resilience. Further, it was found that inherent resilience is not the opposite of social vulnerability, but a distinctly different construct both conceptually and empirically. While understanding the overall variability in resilience, the BRIC is easily deconstructed to its component parts to provide guidance to policy makers on where investments in intervention strategies may make a difference in the improvement of scores. Such evidence-based research has an opportunity to influence public policy focused on disaster risk.
•Haematococcus lacustris produces rich amounts of astaxanthin (AXT).•AXT production was improved due to cellular physiology changes induced by pH shock.•Gene expressions related to astaxanthin ...production were increased upon with pH shock.•Other inductive techniques could be combined to increase AXT production.
In this study, the use of pH shock to improve astaxanthin synthesis in Haematococcus lacustris was investigated. It has been found that pH shock (pH = 4.5, 60 s) imposes stress in the cells and induces physiological changes, which result in astaxanthin accumulation. The optimal acid-base combination of pH shock was H2SO4-KOH, which increased the astaxanthin content per cell to 39 ± 6.92% than those of the control. In addition, pH shock can be applied simultaneously with the other inductive strategies such as high irradiance and carbon source supply. When high irradiance was applied simultaneously with pH shock, astaxanthin yield was increased 65 ± 0.541% than control. In addition, astaxanthin content per cell was increased 105 ± 6.66% than those of the control, with the concomitant application of carbon source addition with pH shock. Herein, these novel findings provide a useful technique for producing astaxanthin using H. lacustris.
The growing demand worldwide for proteins and lipids cannot be met by the intensive use of agricultural land currently available. Insect mass cultures as a source for proteins and lipids have been in ...focus for various reasons. An insect with many positive properties is the black soldier fly,
, whose larvae could be used for the sustainable production of proteins and lipids. Furthermore, the larvae produce bioactive substances which could potentially be used for human and animal welfare.
•Carotenoid and phenolics significantly correlated (p<0.05) to antioxidant activities.•Fucoxanthin and gallic acid were the lead compounds responsible for antioxidant activities.•Chaetoceros ...calcitrans and Isochrysis galbana had higher activities than the rest.
Natural antioxidants from sustainable sources are favoured to accommodate worldwide antioxidant demand. In addition to bioprospecting for natural and sustainable antioxidant sources, this study aimed to investigate the relationship between the bioactives (i.e. carotenoid and phenolic acids) and the antioxidant capacities in fucoxanthin‐producing algae. Total carotenoid, phenolic acid, fucoxanthin contents and fatty acid profile of six species of algae (five microalgae and one macroalga) were quantified followed by bioactivity evaluation using four antioxidant assays. Chaetoceros calcitrans and Isochrysis galbana displayed the highest antioxidant activity, followed by Odontella sinensis and Skeletonema costatum which showed moderate bioactivities. Phaeodactylum tricornutum and Saccharina japonica exhibited the least antioxidant activities amongst the algae species examined. Pearson correlation and multiple linear regression showed that both carotenoids and phenolic acids were significantly correlated (p<0.05) with the antioxidant activities, indicating the influence of these bioactives on the algal antioxidant capacities.
We investigated the achievable maxima of optimisation of both growth and physiological condition of the preselected, Baltic green microalgae strains Chlorella vulgaris and Monoraphidium convolutum. ...The optimisation was divided into 3 consecutive stages of 8 days batch cultures, each focused on the effect of different set of factors on microalgae growth. The conditions identified as the most optimal served as a growth rate reference for the subsequent stage. We monitored the algal growth results spectrophotometrically (absorbance), gravimetrically (dry biomass DW) and biochemically (% protein, carbohydrates, lipids of DW). From the latter, it was possible to infer the physiological state of the microalgae and thus the presence or absence of a cellular stress factor. Stage 1 concerned the influence of basic culture parameters such as water salinity, medium type, and the use of natural waters in place of artificial media (i.e., fresh/brackish, environmental/artificial); stage 2 - the impact of the nitrogen source and its concentration (organic/inorganic, diluted/concentrated) and carbonates addition. Finally, stage 3 concentrated on the influence of the photoperiod and light spectral composition. The results show that among the different approaches to optimize algal growth, the most noticeable improvement was gained using environmental waters in place of artificial ones as a base for preparing the culture medium. Culture on natural, fresh river water yielded 61.1% and 57.4% higher biomass DW/L for C.vulgaris and M.convolutum respectively. For brackish waters, the use of natural bay water (6.7 PSU) in place of an artificial equivalent (distilled water + sea salt) resulted in 33.9% and 28.7% higher DW/L value. Selecting the optimal nitrogen source accelerated biomass production by another 10% for C.vulgaris, while no clear nitrogen source preference was observed for M.convolutum. Modifications to the photoperiod and wavelength of light proved efficient growth with continuous exposure to white light (24h) and highlighted achieved similar growth results with red or blue light in addition to white light in the 12h White/12h Colour photoperiod. In summary, with the use of multi-stage optimization, efficient and physiologically optimized growth was achieved, approximately 57% higher in final biomass DW/L regarding standard conditions, for both green algae strains. We discussed the the advantages of using natural waters and the opportunities presented by the physiological adaptation of brackish strains for growth on fresh and brackish water - the controlled application of salinity stress using local environmental waters in mass culture.
.
•Enriched natural water doubles algae growth relative to artificial media.•Multistage optimization is required to know & improve algal physiological condition.•Brackish strains, due to adaptation to salinity, have potential in two-phase culture.•Biochemical composition and absorbance of pigments tracks physiological stress.
"The Sixties." The powerful images conveyed by those two words have
become an enduring part of American cultural and political history.
But where did Sixties radicalism come from? Who planted the
...intellectual seeds that brought it into being? These questions are
answered with striking clarity in Andrew Jamison and Ron Eyerman's
book. The result is a combination of history and biography that
vividly portrays an entire culture in transition. The authors focus
on specific individuals, each of whom in his or her distinctive way
carried the ideas of the 1930s into the decades after World War II,
and each of whom shared in inventing a new kind of intellectual
partisanship. They begin with C. Wright Mills, Hannah Arendt, and
Erich Fromm and show how their work linked the "old left" of the
Thirties to the "new left" of the Sixties. Lewis Mumford, Rachel
Carson, and Fairfield Osborn laid the groundwork for environmental
activism; Herbert Marcuse, Margaret Mead, and Leo Szilard
articulated opposition to the postwar "scientific-technological
state." Alternatives to mass culture were proposed by Allen
Ginsberg, James Baldwin, and Mary McCarthy; and Saul Alinsky,
Dorothy Day, and Martin Luther King, Jr., made politics personal.
This is an unusual book, written with an intimacy that brings to
life both intellect and emotion. The portraits featured here
clearly demonstrate that the transforming radicalism of the Sixties
grew from the legacy of an earlier generation of thinkers. With a
deep awareness of the historical trends in American culture, the
authors show us the continuing relevance these partisan
intellectuals have for our own age. "In a time colored by
'political correctness' and the ascendancy of market liberalism, it
is well to remember the partisan intellectuals of the 1950s. They
took sides and dissented without becoming dogmatic. May we be able
to say the same about ourselves." -from Chapter 7
In this work, the performance of a vertical multiplate photobioreactor is analyzed and presented. The photobioreactor consisted of 20 vertical plates (1 m2 each) connected by manifolds and a working ...volume of 1300 L. The total area occupied (footprint) was 10 m2, while the illuminated area was 40 m2, therefore the ratio of illuminated area to volume ratio was about 30 m−1. The performance of the photobioreactor was evaluated using a culture of Synechocystis PCC 6803, circulated by a centrifuge pump. The results showed that the amount of light captured by the photobioreactor at a plate spacing of 0.5 m was 90.2 % of the light incident on the horizontal surface, while at a plate spacing of 1.0 m, 50.3 % was captured. The corresponding biomass yield, calculated based on the ground area occupied by the reactor, was 26.0 g m−2 day−1 and 7.2 g m−2 day−1, when the plates were spaced at 0.5 m and 1.0 m respectively. Therefore, the light conversion efficiency calculated based on the ground area was significantly higher in the configuration with a plate spacing of 0.5 m, reaching 5.43 % based on PAR (photosynthetically active radiation), and 2.44 % based on solar radiation, giving a value 3.7 higher than when the plates were spaced 1.0 m apart. It was concluded that the light conversion efficiency might be further improved by reducing the plate spacing while also reducing the culture light path.
Display omitted
•A novel vertical PBR design for efficient production of microalgae is proposed.•The light conversion efficiency was higher when the plates were spaced 0.5 m apart.•The photobioreactor was successfully tested outdoors with a Synechocystis culture.•The photobioreactor can be easily converted for outdoor photobiological H2 production.
PDF
