Microalgal Biorefineries for Bioenergy Production: Can We Move from Concept to Industrial Reality?

Biorefineries are commercial facilities that transform raw materials into commodities of considerable interest to the world bioeconomy. In addition, biorefineries have the potential to achieve favorable environmental characteristics, such as minimal greenhouse gas (GHG) emissions and a lower water footprint, compared to homologous fossil fuels. However, for this concept to become efficient and viable, the use of potentially abundant and specific renewable biological feedstocks should be considered, such as microalgae biomass and other generated products. However, there is an emerging need to consolidate industrial plants that are not only affected by market fluctuations but also aim to transform biological materials into industrially usable products. Thus, for a microalgae biorefinery to compete with the resilient oil refineries in the future, process integration in the supply chain is a promising engineering approach, associating all the components from the cultivation to obtain multiple products that are economically and environmentally sustainable. Therefore, the objective of this review is to compile issues related to microalgal biorefineries applied to bioenergy and biofuel production.     

Personalized In Vitro Cancer Modeling — Fantasy or Reality?

With greater technological advancements and understanding of pathophysiology, “personalized medicine” has become a more realistic goal. In the field of cancer, personalized medicine is the ultimate objective, as each cancer is unique and each tumor is heterogeneous. For many decades, researchers have relied upon studying the histopathology of tumors in the hope that it would provide clues to understanding the pathophysiology of cancer. Current preclinical research relies heavily upon two-dimensional culture models. However, these models have had limited success in recreating the complex interactions between cancer cells and the stroma environment in vivo. Thus, there is increasing impetus to shift to three-dimensional models, which more accurately reflect this phenomenon. With a more accurate in vitro tumor model, drug sensitivity can be tested to determine the best treatment option based on the tumor characteristics. Many methods have been developed to create tumor models or “tumoroids,” each with its advantages and limitations. One significant problem faced is the replication of angiogenesis that is characteristic of tumors in vivo. Nonetheless, if three-dimensional models could be standardized and implemented as a preclinical research tool for therapeutic testing, we would be taking a step towards making personalized cancer medicine a reality.     

Farewell to the Lose–Lose Reality of Policing Plant Imports

In an age of free international shipments of mail-ordered seeds and plants, more policing will not stop the global migration of hitchhiking pests. The solution is in a preemptive response based on an internationally coordinated genomic deployment of global biodiversity in the largest breeding project since the “Garden of Eden.” This plan will enrich the narrow genetic basis of annual and perennial plants with adaptations to changing environments and resistances to the pests of the future.

“Plan for what is difficult while it is easy; do what is great while it is small.”—Sun Tzu, The Art of War

When 182 countries become party to a common cause, it is reason to rejoice. Such an opportunity was provided when the Food and Agriculture Organization of the United Nations (FAO) approved the International Plant Protection Convention (IPPC) on December 6, 1951, with the objective of developing and implementing international phytosanitary standards to reduce the risks associated with the spread of plant pests to agriculture and natural ecosystems [1]. Over the years, the IPPC has been amended to enforce safer trade of plants by preventing the entry and spread of new pests. This led to the establishment of dedicated government agencies, usually associated with the ministries of agriculture, which are responsible for inspecting and policing against the entry of pests. These agencies have grown tremendously over the years because their noble mission is simply to explain to the “want to do good” elected officials who are responsible for the allocation of funds. However, the IPPC is currently implementing a losing defensive strategy, for which a scientific alternative based on a broad view of our interconnected global reality is presented below.     

Sustainable Water Management in the Southwestern United States: Reality or Rhetoric?

Background

While freshwater sustainability is generally defined as the provisioning of water for both people and the environment, in practice it is largely focused only on supplying water to furnish human population growth. Symptomatic of this is the state of Arizona, where rapid growth outside of the metropolitan Phoenix-Tucson corridor relies on the same groundwater that supplies year-round flow in rivers. Using Arizona as a case study, we present the first study in the southwestern United States that evaluates the potential impact of future population growth and water demand on streamflow depletion across multiple watersheds.

Methodology/Principal Findings

We modeled population growth and water demand through 2050 and used four scenarios to explore the potential effects of alternative growth and water management strategies on river flows. Under the base population projection, we found that rivers in seven of the 18 study watersheds could be dewatered due to municipal demand. Implementing alternative growth and water management strategies, however, could prevent four of these rivers from being dewatered.

Conclusions/Significance

The window of opportunity to implement water management strategies is narrowing. Because impacts from groundwater extraction are cumulative and cannot be immediately reversed, proactive water management strategies should be implemented where groundwater will be used to support new municipal demand. Our approach provides a low-cost method to identify where alternative water and growth management strategies may have the most impact, and demonstrates that such strategies can maintain a continued water supply for both people and the environment.     

Is Bocourt’s Terrific Skink Really So Terrific? Trophic Myth and Reality

Many scientists argue that our planet is undergoing a mass extinction event that is largely due to human influences. In this context, rediscoveries of species presumed to be extinct are encouraging and of great potential interest. During a 2003 expedition to New Caledonia, Bocourt’s terrific skink, Phoboscincus bocourti, was unexpectedly rediscovered on a small islet by one of us. This skink species had been described from a single specimen collected around 1872 in New Caledonia. Since that time, however, no data on the species’ biology, trophic interactions, or role in the ecosystem have been collected, making it difficult to follow the established conservation plan. In this study, we used a multidisciplinary approach involving natural history, anatomy, morphology, genetics, and stable isotopes to elucidate the ecology of Bocourt’s terrific skink. Over the course of three different expeditions to the islet (total of 55 days across 2005 and 2012), we captured 4 individuals and observed another 4 individuals. The species’ dentition and trophic ecology suggest that it is a top predator in its ecosystem and a major consumer of small terrestrial reptiles. Its high degree of genetic relatedness to another New Caledonian skink, which has a broad distribution, suggests that P. bocourti underwent genetic isolation at a geographical remote location, where dispersal or colonization was highly improbable. Moreover, the lack of genetic variation among the four individuals we captured may imply that a unique lineage, characterized by few inter-island exchanges, exists on the islet. Bocourt’s terrific skink may be the largest terrestrial squamate predator alive in New Caledonia today. As a result, it is likely vulnerable to habitat modifications and especially the invasive rodents found on this islet. Further information is necessary to assess the conservation plans and practices in place as no concrete changes have been made since the species’ rediscovery almost 10 years ago.     

Natural Scientific and Theological Approaches to Understanding How the Existing Reality “Is Arranged”

Biophysics - This paper discusses whether natural sciences suffice to explain everything that happens in our reality or whether “higher forces” that do not fit into the materialistic...     

Where does heteroclisis come from? Evidence from Romanian dialects

This study examines some cases of heteroclisis in the history of Romanian dialects, and concludes that the data call for a reconsideration of Stump’s distinction (Language 82:279–322, 2006) between ‘cloven’ heteroclisis, where the intraparadigmatic ‘split’ is aligned with some morphosyntactic feature distinction, and ‘fractured’ heteroclisis, where this is not the case and the pattern of heteroclisis is purely morphological. Stump’s account creates the impression that the ‘cloven’ variety is universally predominant, and that the ‘fractured’ variety tends to follow very closely the available ‘cloven’ patterns of the language. I shall suggest, instead, that the ‘fractured-only’ situation may in fact underlie heteroclisis cross-linguistically, the phenomenon being in general sensitive not directly to morphosyntactic content, but rather to characteristic, and often purely ‘morphomic’, patterns of stem-allomorphy. Research for this paper was undertaken as part of the Arts and Humantities Research Council-funded project Autonomous Morphology in Diachrony: comparative evidence from the Romance Languages, currently being conducted at Oxford University.     

Initial soil organic carbon stocks govern changes in soil carbon: Reality or artifact?

Changes in soil organic carbon (SOC) storage have the potential to affect global climate; hence identifying environments with a high capacity to gain or lose SOC is of broad interest. Many cross-site studies have found that SOC-poor soils tend to gain or retain carbon more readily than SOC-rich soils. While this pattern may partly reflect reality, here we argue that it can also be created by a pair of statistical artifacts. First, soils that appear SOC-poor purely due to random variation will tend to yield more moderate SOC estimates upon resampling and hence will appear to accrue or retain more SOC than SOC-rich soils. This phenomenon is an example of regression to the mean. Second, normalized metrics of SOC change—such as relative rates and response ratios—will by definition show larger changes in SOC at lower initial SOC levels, even when the absolute change in SOC does not depend on initial SOC. These two artifacts create an exaggerated impression that initial SOC stocks are a major control on SOC dynamics. To address this problem, we recommend applying statistical corrections to eliminate the effect of regression to the mean, and avoiding normalized metrics when testing relationships between SOC change and initial SOC. Careful consideration of these issues in future cross-site studies will support clearer scientific inference that can better inform environmental management.     

Poikilothermic traits in Mashona mole-rat (Fukomys darlingi). Reality or myth?

The African mole-rats (Bathyergidae, Rodentia) is a mammalian family well known for a variety of ecophysiological adaptations for strictly belowground life. The smallest bathyergid, the hairless naked mole-rat from arid areas in Eastern Africa, is even famous as the only truly poikilothermic mammal. Another bathyergid, the Mashona mole-rat (Fukomys darlingi) from Zimbabwe, is supposed to have strong poikilothermic traits, because it is not able to maintain a stable body temperature at ambient temperatures below 20 °C. This is surprising because, compared to the naked mole-rat, this species, together with all congenerics, is larger, haired, and living in more seasonal environment. In addition, other Fukomys mole-rats show typical mammalian pattern in resting metabolic rates. In our study, we measured resting metabolic rate and body temperature of Mashona mole-rats from Malawi across a gradient of ambient temperatures to test its poikilothermic traits. We found that the adult mass specific resting metabolic rate was 0.76±0.20 ml O₂ g⁻¹ h⁻¹ and body temperature 34.8±1.1 °C in the thermoneutral zone (27–34 °C). Body temperature was stable (33.0±0.5 °C) at ambient temperatures from 10 to 25 °C. We thus cannot confirm poikilothermic traits in this species, at least for its Malawian population. Factors potentially explaining the observed discrepancy in Mashona mole-rat energetics are discussed.     

Message from the Editor-in-Chief

The current issue of Acta Biochimica et Biophysica Sinica (ABBS) has turned a new page of this journal since its publication forty five years ago. It is perhaps an appropriate time to share with our readers about the evolution of this journal, the changes that have taken place, and the future that we are looking forward to. ABBS was first established in 1958 with Professor Ying-Lai WANG as the founding Editor-in-Chief and has been ever since an     

What Do We Learn from Spheroid Culture Systems? Insights from Tumorspheres Derived from Primary Colon Cancer Tissue

Due to their self-renewal and tumorigenic properties, tumor-initiating cells (TICs) have been hypothesized to be important targets for colorectal cancer (CRC). However the study of TICs is hampered by the fact that the identification and culturing of TICs is still a subject of extensive debate. Floating three-dimensional spheroid cultures (SC) that grow in serum-free medium supplemented with growth factors are supposed to be enriched in TICs. We generated SC from fresh clinical tumor specimens and compared them to SC isolated from CRC cell-lines as well as to adherent differentiated counterparts. Patient-derived SC display self-renewal capacity and can induce serial transplantable tumors in immuno-deficient mice, which phenotypically resemble the tumor of origin. In addition, the original tumor tissue and established SC retain several similar CRC-relevant mutations. Primary SC express key stemness proteins such as SOX2, OCT4, NANOG and LGR5 and importantly show increased chemoresistance ability compared to their adherent differentiated counterparts and to cell line-derived SC. Strikingly, cells derived from spheroid or adherent differentiating culture conditions displayed similar self-renewal capacity and equally formed tumors in immune-deficient mice, suggesting that self-renewal and tumor-initiation capacity of TICs is not restricted to phenotypically immature spheroid cells, which we describe to be highly plastic and able to reacquire stem-cell traits even after long differentiation processes. Finally, we identified two genes among a sphere gene expression signature that predict disease relapse in CRC patients. Here we propose that SC derived from fresh patient tumor tissue present interesting phenotypic features that may have clinical relevance for chemoresistance and disease relapse and therefore represent a valuable tool to test for new CRC-therapies that overcome drug resistance.     

Production of steviol from steviol glucosides using β-glycosidase from Sulfolobus solfataricus

Steviol is a diterpene isolated from the plant Stevia rebaudiana that has a potential role as an antihyperglycemic agent by stimulating insulin secretion from pancreatic beta cells and also has significant potential to diminish the renal clearance of anionic drugs and their metabolites. In this study, the lacS gene, which encodes a thermostable β-glycosidase (SSbgly) enzyme from the extremely thermoacidophillic archaeon Sulfolobus solfataricus, was cloned and expressed in E. coli Rossetta BL21(DE3)pLyS using lactose as an inducer. Through fermentation, SSbgly was expressed as a 61 kDa protein with activity of 24.3 U/mg and the OD₆₀₀ of 23 was reached after 18 h induction with 10 mM lactose. Purified protein was obtained by Ni-Sepharose chromatography with a yield of 92.3%. SSbgly hydrolyzed steviol glycosides to produce steviol with a yield of 99.2%. The optimum conditions for steviol production were 50 U/ml SSbgly and 90 mg/ml Ste at 75 °C as determined by the response surface method.     

Skill Memory Escaping from Distraction by Sleep��Evidence from Dual-Task Performance

Background

Sleep facilitates off-line consolidation of memories, as shown for learning of motor skills in the absence of concomitant distractors. We often perform complex tasks focusing our attention mostly on one single part of them. However, we are equally able to skillfully perform other concurrent tasks. One may even improve performance on disregarded parts of complex tasks, which were learned implicitly. In the present study we investigated the role of sleep in the off-line consolidation of procedural skills when attention is diverted from the procedural task because of interference from a concurrent task.

Methodology/Principal Findings

We used a dual-task paradigm containing (i) procedural serial reaction time task (SRTT), which was labeled as subordinate and unimportant and (ii) declarative word-pair association task (WPAT), performed concomitantly. The WPAT served as a masked distractor to SRTT and was strongly reinforced by the instructions. One experimental and three control groups were tested. The experimental group was re-tested after two nights of sleep (sleep group, SG). The first control group had sleep deprivation on the first post-learning night (nighttime-awake group, NA), the second control group was tested in the morning and then re-tested after 12-hours (daytime-awake group, DA); the third one had the same assignments as DA but with a subsequent, instead of a concomitant, WPAT (daytime-awake-subsequent-WPAT group, DAs). We found SRTT performance gains in SG but not in NA and DA groups. Furthermore, SG reached similar learning gains in SRTT as the DAs group, which gained in SRTT performance because of post-training interference from the declarative task.

Conclusions/Significance

The results demonstrate that sleep allows off-line consolidation, which is resistant to deteriorating effects of a reinforced distractor on the implicit procedural learning and allowing for gains which are consistent with those produced when inhibited declarative memories of SRTT do not compete with procedural ones.     

Psychrophilic α-amylase from Aeromonas veronii NS07 isolated from farm soils

Among 120 isolates examined in this study, three isolates were selected for amylase production on starch agar plates following incubation at 10 °C. Identification by 16SrRNA on selected bacterium disclosed the highest similarity for protean regions of this gene as Aeromonas veronii NS07. A 63 kDa psychrophilic amylase enzyme from NS07 strain was purified by two-steps chromatography. The enzyme had the highest specific activity at pH 4 and was active at the range of temperatures from 0 to 50 °C, although the optimum temperature for enzyme activity was found at 10 °C. Analysis of the N-terminal amino acid sequencing disclosed 20 amino acids from purified amylase which had no similarity with other known α-amylases, indicating that the presented enzyme was novel. Amylase activity was enhanced in relation to optimum activity with the presence of sodium sulphate (161%), MnCl₂ (298%), CaCl₂ (175%), FeCl₂ (182%), MgCl₂ (237%), ZnCl₂ (169%), NiCl₂ (139%), NaCl (158%), each at 5 mM, while EDTA, phenylmethane sulphonylfluoride (PMSF) (3 mM), urea (8 M) and SDS (1%) inhibited the enzyme up to 5%, 2%, 80% and 18%, respectively. NS07 strain seems to be suitable as biocatalyst for practical use in liquefaction of starch at low temperatures, detergent and textile industries.     

Synthesis of cello-oligosaccharides from cellobiose with β-glucosidase II from Aspergillus niger

An extracellular -glucosidase II of Aspergillus niger catalysed the synthesis of cello-oligosaccharides from cellobiose (15%, w/v). The enzyme was stable at and below 4°C for at least 230 days and also stable at 30°C with the presence of 2.0% (w/v) cellobiose. The maximum yield of cello-oligosaccharides was about 30% (mol/mol), based on cellobiose (130 mg/mL) consumed. © Rapid Science Ltd. 1998