The effects of algal extracellular substances on algal growth, metabolism and long-term medium recycle, and inhibition alleviation through ultrasonication

2018 ◽  
Vol 267 ◽  
pp. 192-200 ◽  
Author(s):  
Ze Yu ◽  
Haiyan Pei ◽  
Qingjie Hou ◽  
Changliang Nie ◽  
Lijie Zhang ◽  
...  
Keyword(s):  
Algal Growth ◽  
Growth Metabolism ◽  
Extracellular Substances

scholarly journals A 40-million-year history of atmospheric CO 2

2013 ◽  
Vol 371 (2001) ◽  
pp. 20130096 ◽  
Author(s):  
Yi Ge Zhang ◽  
Mark Pagani ◽  
Zhonghui Liu ◽  
Steven M. Bohaty ◽  
Robert DeConto
Keyword(s):  
Middle Miocene ◽  
Carbon Fixation ◽  
Middle Eocene ◽  
Ice Sheet ◽  
Algal Growth ◽  
Equatorial Atlantic ◽  
Antarctic Ice Sheet ◽  
The Past ◽  
Wide Range

The alkenone– p CO 2 methodology has been used to reconstruct the partial pressure of ancient atmospheric carbon dioxide ( p CO 2 ) for the past 45 million years of Earth's history (Middle Eocene to Pleistocene epochs). The present long-term CO 2 record is a composite of data from multiple ocean localities that express a wide range of oceanographic and algal growth conditions that potentially bias CO 2 results. In this study, we present a p CO 2 record spanning the past 40 million years from a single marine locality, Ocean Drilling Program Site 925 located in the western equatorial Atlantic Ocean. The trends and absolute values of our new CO 2 record site are broadly consistent with previously published multi-site alkenone–CO 2 results. However, new p CO 2 estimates for the Middle Miocene are notably higher than published records, with average p CO 2 concentrations in the range of 400–500 ppm. Our results are generally consistent with recent p CO 2 estimates based on boron isotope-pH data and stomatal index records, and suggest that CO 2 levels were highest during a period of global warmth associated with the Middle Miocene Climatic Optimum (17–14 million years ago, Ma), followed by a decline in CO 2 during the Middle Miocene Climate Transition (approx. 14 Ma). Several relationships remain contrary to expectations. For example, benthic foraminiferal δ 18 O records suggest a period of deglaciation and/or high-latitude warming during the latest Oligocene (27–23 Ma) that, based on our results, occurred concurrently with a long-term decrease in CO 2 levels. Additionally, a large positive δ 18 O excursion near the Oligocene–Miocene boundary (the Mi-1 event, approx. 23 Ma), assumed to represent a period of glacial advance and retreat on Antarctica, is difficult to explain by our CO 2 record alone given what is known of Antarctic ice sheet history and the strong hysteresis of the East Antarctic Ice Sheet once it has grown to continental dimensions. We also demonstrate that in the Neogene with low CO 2 levels, algal carbon concentrating mechanisms and spontaneous biocarbonate–CO 2 conversions are likely to play a more important role in algal carbon fixation, which provides a potential bias to the alkenone– p CO 2 method.

scholarly journals Rapid multi-generational acclimation of coralline algal reproductive structures to ocean acidification

2021 ◽  
Vol 288 (1950) ◽  
Author(s):  
B. Moore ◽  
S. Comeau ◽  
M. Bekaert ◽  
A. Cossais ◽  
A. Purdy ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Growth Rates ◽  
Natural Habitat ◽  
Algal Growth ◽  
Coralline Algae ◽  
Reproductive Structures ◽  
Highly Sensitive ◽  
Negative Effect ◽  
Coral Reef Ecosystems

The future of coral reef ecosystems is under threat because vital reef-accreting species such as coralline algae are highly susceptible to ocean acidification. Although ocean acidification is known to reduce coralline algal growth rates, its direct effects on the development of coralline algal reproductive structures (conceptacles) is largely unknown. Furthermore, the long-term, multi-generational response of coralline algae to ocean acidification is extremely understudied. Here, we investigate how mean pH, pH variability and the pH regime experienced in their natural habitat affect coralline algal conceptacle abundance and size across six generations of exposure. We show that second-generation coralline algae exposed to ocean acidification treatments had conceptacle abundances 60% lower than those kept in present-day conditions, suggesting that conceptacle development is initially highly sensitive to ocean acidification. However, this negative effect of ocean acidification on conceptacle abundance disappears after three generations of exposure. Moreover, we show that this transgenerational acclimation of conceptacle development is not facilitated by a trade-off with reduced investment in growth, as higher conceptacle abundances are associated with crusts with faster growth rates. These results indicate that the potential reproductive output of coralline algae may be sustained under future ocean acidification.

scholarly journals Investigating the Growth of Algae Under Low Atmospheric Pressures for Potential Food and Oxygen Production on Mars

2021 ◽  
Vol 12 ◽  
Author(s):  
Leena M. Cycil ◽  
Elisabeth M. Hausrath ◽  
Douglas W. Ming ◽  
Christopher T. Adcock ◽  
James Raymond ◽  
...  
Keyword(s):  
Life Support ◽  
Light Exposure ◽  
Algal Growth ◽  
Continuous Light ◽  
Low Pressure ◽  
Snow Algae ◽  
Bioregenerative Life Support System ◽  
Potential Food ◽  
Bioregenerative Life Support

With long-term missions to Mars and beyond that would not allow resupply, a self-sustaining Bioregenerative Life Support System (BLSS) is essential. Algae are promising candidates for BLSS due to their completely edible biomass, fast growth rates and ease of handling. Extremophilic algae such as snow algae and halophilic algae may also be especially suited for a BLSS because of their ability to grow under extreme conditions. However, as indicated from over 50 prior space studies examining algal growth, little is known about the growth of algae at close to Mars-relevant pressures. Here, we explored the potential for five algae species to produce oxygen and food under low-pressure conditions relevant to Mars. These included Chloromonas brevispina, Kremastochrysopsis austriaca, Dunaliella salina, Chlorella vulgaris, and Spirulina plantensis. The cultures were grown in duplicate in a low-pressure growth chamber at 670 ± 20 mbar, 330 ± 20 mbar, 160 ± 20 mbar, and 80 ± 2.5 mbar pressures under continuous light exposure (62–70 μmol m–2 s–1). The atmosphere was evacuated and purged with CO2 after sampling each week. Growth experiments showed that D. salina, C. brevispina, and C. vulgaris were the best candidates to be used for BLSS at low pressure. The highest carrying capacities for each species under low pressure conditions were achieved by D. salina at 160 mbar (30.0 ± 4.6 × 105 cells/ml), followed by C. brevispina at 330 mbar (19.8 ± 0.9 × 105 cells/ml) and C. vulgaris at 160 mbar (13.0 ± 1.5 × 105 cells/ml). C. brevispina, D. salina, and C. vulgaris all also displayed substantial growth at the lowest tested pressure of 80 mbar reaching concentrations of 43.4 ± 2.5 × 104, 15.8 ± 1.3 × 104, and 57.1 ± 4.5 × 104 cells per ml, respectively. These results indicate that these species are promising candidates for the development of a Mars-based BLSS using low pressure (∼200–300 mbar) greenhouses and inflatable structures that have already been conceptualized and designed.

Long-term joint effect of nutrients and temperature increase on algal growth in Lake Taihu, China

2011 ◽  
Vol 23 (2) ◽  
pp. 222-227 ◽  
Author(s):  
Chun Ye ◽  
Zhemin Shen ◽  
Tao Zhang ◽  
Maohong Fan ◽  
Yangming Lei ◽  
...  
Keyword(s):  
Temperature Increase ◽  
Lake Taihu ◽  
Algal Growth ◽  
Joint Effect

A Comparison of Methods for Assessment of Nutrient Deficiency of Phytoplankton in a Large Oligotrophic Lake

1990 ◽  
Vol 47 (12) ◽  
pp. 2328-2338 ◽  
Author(s):  
Walter K. Dodds ◽  
John C. Priscu
Keyword(s):  
Thermal Stratification ◽  
Carbon Fixation ◽  
Algal Growth ◽  
Nutrient Deficiency ◽  
Short Term ◽  
P Deficiency ◽  
Flathead Lake ◽  
Dark Carbon Fixation ◽  
Nutrient Amendments

Short-term (h) and Song-term (d) changes in phytoplankton community physiology and bsomass in response to nutrient enrichment were used concomitantly as bioassays of phytoplankton nutrient deficiency in oligotrophic Flathead Lake, Montana, six times over the course of a year. Long-term bioassays consisted of nutrient amendments to epilimnetic water in 20 L containers which were subsequently monitored for algal growth. Short-term bioassays included measurement of NH4+ stimulation of dark carbon fixation, measurement of PO43− and NH4+ uptake over time to assess depletion of internal pools and stimulation effects of PO43− on NH4+ uptake and NH4+ on PO43− uptake. During thermal stratification, simultaneous additions of NH4+ and PO43− in long-term bioassays caused significant increases in chlorophyll a concentration, photosynthetic 14CO2 uptake, and particulate N concentration within 4.5 d; single additions of NH4+ or PO43− had little or no effect. During winter mixing there was little evidence for N or P deficiency in either short- or long-term bioassays. In general, short-term bioassays did not consistently agree with each other or with long-term bioassays. Our results suggest that it may be necessary to elicit growth of phytoplankton with nutrient addition to make definitive statements regarding nutrient deficiency.

scholarly journals Use of Alternative Containers for Long- and Short-term Greenhouse Crop Production

2015 ◽  
Vol 25 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Renee Conneway ◽  
Sven Verlinden ◽  
Andrew K. Koeser ◽  
Michael Evans ◽  
Rebecca Schnelle ◽  
...  
Keyword(s):  
Crop Production ◽  
Algal Growth ◽  
Consumer Preference ◽  
Dry Weight ◽  
Short Term ◽  
Greenhouse Production ◽  
Greenhouse Crops ◽  
Shoot Dry Weight ◽  
Puncture Strength

While research on the use of alternative containers for greenhouse production is growing, most studies have focused on a limited number of types of alternative containers and primarily on short-term greenhouse crops. With the recent release of several new bioplastic alternatives, comparisons to established alternative containers and production of longer rotation ornamental crops should be investigated. Our work, therefore, investigates the performance of ten commercially available alternative containers and their effects on both a short-term ‘Sunpatiens Compacta’ impatiens (Impatiens ×hybrida) and a long-term greenhouse crop ‘Elegans Ice’ lavender (Lavendula angustifolia) at four different locations. Results indicated that plant growth in terms of dry weight differed by container at most locations. Combined analysis of all locations showed that only straw and a bioplastic sleeve outperformed plastic pots in terms of shoot dry weight and then only after 12 weeks of production. Leachate pH, but not electrical conductivity (EC), varied by container in both the short- and long-term crop with alternative containers made from composted cow manure and peat showing consistently higher and lower pH readings, respectively. Postharvest container strength varied significantly by container, with the plastic control maintaining the highest puncture resistance after both 6 and 12 weeks, in some instances matched by the puncture strength of coconut fiber pots. Some alternative containers, in particular, wood, manure, and peat showed algal growth after 6 and 12 weeks of greenhouse production. We conclude that while some alternative containers were linked to increased growth, most showed growth equal to the plastic control, and could therefore make appropriate alternatives to plastic pots. However, changes in pH, low puncture strengths after production, higher denesting times, and algal growth on manure, wood, and peat may make these pots less desirable alternatives than other pots under investigation. However, other factors not studied here, such as compostability, biodegradability in the landscape, water use, consumer preference, aesthetics, compatibility with mechanized operations, and cost may also need to be taken into account when deciding on an appropriate container for greenhouse production.

scholarly journals Assessment of long term interaction between the endemic seagrass P. oceanica and the exotic green alga C. cylindracea in the South Eastern coast of Spain (Murcia Region)

2015 ◽  
Author(s):  
Jaime Bernardeau-Esteller ◽  
Rocio García-Muñoz ◽  
Lázaro Marín-Guirao ◽  
Jose Miguel Sandoval-Gil ◽  
Ruiz Juan Fernandez
Keyword(s):  
Green Alga ◽  
Algal Growth ◽  
Interactive Effects ◽  
Limiting Factors ◽  
Eastern Coast ◽  
Future Research ◽  
The South ◽  
South Eastern ◽  
Leaf Canopy

The green alga Caulerpa cylindracea has rapidly spread throughout the Western Mediterranean during the last 20 years. Compared with other native benthic communities, Posidonia oceanica meadows seems to be highly resistant to the colonization by the alga. Nonetheless, it is suggested that in the long-term C. cylindracea could affect the seagrass altering its vitality, structure and functions, however little is known about the interactive effects between these two structuring species. To this end, the abundance of both macrophytes was quantified and monitored in invaded and non-invaded localities of the South Eastern coast of Spain (Murcia Region) over an 8-year period (2007-2014). Results indicate that no differences were highlighted between invaded and no invaded meadows and all the monitored meadows showed stable or progressive trends in shoot density, meadow cover and net population growth. Regardless of the depth, in all of the invaded localities C. cylindracea biomass present inside the seagrass leaf canopy was about 10 to 50–fold lower than that measured just outside the leaf canopy. In summary, our results do not support the existence of a long-term competitive interaction between the invasive alga and the native seagrass, at least in the studied meadows and at the meadow level. C. cylindracea forms huge biomass gradients associated to the seagrass meadow edges that are stable with time, which suggests the existence of highly limiting conditions for algal growth and survival under the P. oceanica leaf canopy. Future research on such limiting factors could help us to understand the invasive capacity of the alga and the factors involved in the resistance of native habitats to bioinvasions.

Study on the Causes and Prevention Countermeasures of Algal Bloom for Wuliangsuhai Lake in Inner Mongolia

2012 ◽  
Vol 550-553 ◽  
pp. 1076-1079
Author(s):  
Zhong Feng Jiang ◽  
Chang You Li ◽  
Sheng Zhang
Keyword(s):  
Sustainable Development ◽  
Inner Mongolia ◽  
Regional Economy ◽  
Algal Bloom ◽  
Algal Growth ◽  
The State ◽  
Monitoring Data ◽  
The Sustainable Development ◽  
Water Eutrophication

“Algal Bloom” have been broken in Wuliangsuhai lake in May 2008 and in May 2009, this situation has caused some loss of lake inherent function,for example aquaculture, irrigation, tourism and so on, at the same time,severely restricting the sustainable development of regional economy. It is a very important Question for “algal Bloom” need to be concerned of leads and scholars.Water quality, hydrology, meteorology etc Monitoring data were analyzed for the "algal Bloom" period. The results show: The main reasons of “algal Bloom” were many beneficial factors for algal growth and water eutrophication in the state of long-term.

Sign in / Sign up

Export Citation Format

Share Document