Grain and Nutritional Quality Traits of Southwestern U.S. Blue Maize Landraces

Anthocyanin‐rich Southwestern blue maize (Zea mays L.) landraces are receiving interest as functional foods, and commercial production is increasing. We determined variation in kernel color, anthocyanin content, texture, and selected compositional traits of representative varieties. In 2013, eight varieties were grown at four locations in New Mexico. Total kernel anthocyanin content (TAC) and component pigments were measured with spectrophotometry and HPLC, respectively. Oil, protein, starch, and kernel density were determined using NIR spectroscopy and amino acid concentrations using wet chemistry. An average of 49.6 mg/100 g of TAC with a range of 17.6–65.1 mg/100 g was observed. Cyanidin and pelargonidin were major components, and peonidin and succinyl 3‐glucoside were minor components. Low levels of disuccinyl glucoside were detected. Blue kernels were higher in anthocyanin than purple or red kernels. Floury kernels displayed the highest protein and oil contents and the lowest starch content and kernel density. The highest starch and kernel density levels were observed in small flint/dent and pop‐flint/dent kernels. Amino acid content was variable across genotypes and locations

Phytoene Accumulation in the Novel Microalga Chlorococcum sp. Using the Pigment Synthesis Inhibitor Fluridone

Carotenoids are lipophilic pigments found in plants and algae, as well as some bacteria, archaea, and fungi that serve two functions—(1) as light harvesting molecules—primary carotenoids, and (2) as antioxidants, acting against reactive oxygen species–secondary carotenoids. Because of their strong antioxidant properties, they are also valuable for the development of anti-aging and photo-protective cosmetic applications. Of particular interest is the carotenoid phytoene, for its colorless and UV absorption characteristics. In this study, we targeted a reduction of phytoene desaturase (PDS) activity with the pigment-inhibiting herbicide 1-methyl-3-phenyl-5-[3- (trifluoromethyl)phenyl]pyridin-4-one (fluridone), which leads to the over-accumulation of phytoene in the recently characterized microalgal strain Chlorococcum sp. (UTEX B 3056). After post-incubation with fluridone, phytoene levels were measured at ~33 ug/mg cell tissue, as opposed to non-detectable levels in control cultures. Hence, the novel microalga Chlorococcum sp. is a viable candidate for the production of the high-value carotenoid phytoene and subsequent applications in cosmeceuticals, as well as more obvious nutraceutical and pharmaceutical applications

Identification of regulatory network hubs that control lipid metabolism in Chlamydomonas reinhardtii

HighlightCharacterization of regulatory networks in Chlamydomonas reinhardtii led to the identification of regulatory hubs that control the repatterning of cellular metabolism that leads to triacylglycerol accumulation in microalgae.Microalgae-based biofuels are promising sources of alternative energy, but improvements throughout the production process are required to establish them as economically feasible. One of the most influential improvements would be a significant increase in lipid yields, which could be achieved by altering the regulation of lipid biosynthesis and accumulation. Chlamydomonas reinhardtii accumulates oil (triacylglycerols, TAG) in response to nitrogen (N) deprivation. Although a few important regulatory genes have been identified that are involved in controlling this process, a global understanding of the larger regulatory network has not been developed. In order to uncover this network in this species, a combined omics (transcriptomic, proteomic and metabolomic) analysis was applied to cells grown in a time course experiment after a shift from N-replete to N-depleted conditions. Changes in transcript and protein levels of 414 predicted transcription factors (TFs) and transcriptional regulators (TRs) were monitored relative to other genes. The TF and TR genes were thus classified by two separate measures: up-regulated versus down-regulated and early response versus late response relative to two phases of polar lipid synthesis (before and after TAG biosynthesis initiation). Lipidomic and primary metabolite profiling generated compound accumulation levels that were integrated with the transcript dataset and TF profiling to produce a transcriptional regulatory network. Evaluation of this proposed regulatory network led to the identification of several regulatory hubs that control many aspects of cellular metabolism, from N assimilation and metabolism, to central metabolism, photosynthesis and lipid metabolism

The Regulation of Photosynthetic Structure and Function during Nitrogen Deprivation in Chlamydomonas reinhardtii

The accumulation of carbon storage compounds by many unicellular algae after nutrient deprivation occurs despite declines in their photosynthetic apparatus. To understand the regulation and roles of photosynthesis during this potentially bioenergetically valuable process, we analyzed photosynthetic structure and function after nitrogen deprivation in the model alga Chlamydomonas reinhardtii. Transcriptomic, proteomic, metabolite, and lipid profiling and microscopic time course data were combined with multiple measures of photosynthetic function. Levels of transcripts and proteins of photosystems I and II and most antenna genes fell with differing trajectories; thylakoid membrane lipid levels decreased, while their proportions remained similar and thylakoid membrane organization appeared to be preserved. Cellular chlorophyll (Chl) content decreased more than 2-fold within 24 h, and we conclude from transcript protein and 13C labeling rates that Chl synthesis was down-regulated both pre- and posttranslationally and that Chl levels fell because of a rapid cessation in synthesis and dilution by cellular growth rather than because of degradation. Photosynthetically driven oxygen production and the efficiency of photosystem II as well as P700+ reduction and electrochromic shift kinetics all decreased over the time course, without evidence of substantial energy overflow. The results also indicate that linear electron flow fell approximately 15% more than cyclic flow over the first 24 h. Comparing Calvin-Benson cycle transcript and enzyme levels with changes in photosynthetic 13CO2 incorporation rates also pointed to a coordinated multilevel down-regulation of photosynthetic fluxes during starch synthesis before the induction of high triacylglycerol accumulation rates

Soil Microbial Composition and Soil Health of Reverse-Osmosis-Concentrate and Brackish-Groundwater Irrigated Soils in Southern New Mexico

The phospholipid fatty acid method was used to determine the shifts in microbial biomass due to irrigation with reverse-osmosis (RO) concentrate (or highly saline reject water) and brackish groundwater (BGW). In this greenhouse study, RO concentrate and BGW were applied to irrigate pecan trees for 8 months for two consecutive seasons. The objectives of the study were to (i) evaluate how irrigation with RO concentrate and BGW impacts soil microbial composition in pecan rhizospheres using microbial phospholipid fatty acid (PLFA) biomarkers as indicators, and (ii) evaluate its implications on soil health. Three treatments of RO concentrate (EC = 8.0 dS/m), BGW (EC = 4.0 dS/m), and the city of Las Cruces’s water (EC = 0.8 dS/m) as a control were used to irrigate pecan trees. EC, pH, and organic matter (OM%) content of the soil samples were measured, and PLFA biomarkers for the microbial community were determined. Na-, Cl-, and K-ion concentrations were 26.16, 32.54, and 5.93 meq/L in 2017 and 25.44, 24.26, and 5.49 meq/L in 2018, respectively, in RO irrigation pots. For two seasons, gram-positive bacteria were dominant, while gram-negative bacteria were not detected in the second season. PLFA biomarkers of fungi were found among all three treatments in the first season; however, they appeared only with BGW in the second season. Actinomycetes were recorded in the first season while they were not seen in the second season. Increases in soil salinity and microbial shifts could have important implications for soil health. Irrigating with RO and BGW shifted the soil microbial composition; therefore, long-term irrigation with BGW and RO concentrate would be deleterious for pecan production and soil health

Grain and Nutritional Quality Traits of Southwestern U.S. Blue Maize Landraces

Anthocyanin‐rich Southwestern blue maize (Zea mays L.) landraces are receiving interest as functional foods, and commercial production is increasing. We determined variation in kernel color, anthocyanin content, texture, and selected compositional traits of representative varieties. In 2013, eight varieties were grown at four locations in New Mexico. Total kernel anthocyanin content (TAC) and component pigments were measured with spectrophotometry and HPLC, respectively. Oil, protein, starch, and kernel density were determined using NIR spectroscopy and amino acid concentrations using wet chemistry. An average of 49.6 mg/100 g of TAC with a range of 17.6–65.1 mg/100 g was observed. Cyanidin and pelargonidin were major components, and peonidin and succinyl 3‐glucoside were minor components. Low levels of disuccinyl glucoside were detected. Blue kernels were higher in anthocyanin than purple or red kernels. Floury kernels displayed the highest protein and oil contents and the lowest starch content and kernel density. The highest starch and kernel density levels were observed in small flint/dent and pop‐flint/dent kernels. Amino acid content was variable across genotypes and locations.This article is published as Nankar, Amol, F. Omar Holguin, M. Paul Scott, and Richard C. Pratt. "Grain and nutritional quality traits of southwestern US blue maize landraces." Cereal Chemistry 94, no. 6 (2017): 950-955. doi: 10.1094/CCHEM-04-17-0079-R.</p

Phytoene Accumulation in the Novel Microalga <i>Chlorococcum</i> sp. Using the Pigment Synthesis Inhibitor Fluridone

Carotenoids are lipophilic pigments found in plants and algae, as well as some bacteria, archaea, and fungi that serve two functions&#8212;(1) as light harvesting molecules&#8212;primary carotenoids, and (2) as antioxidants, acting against reactive oxygen species&#8211;secondary carotenoids. Because of their strong antioxidant properties, they are also valuable for the development of anti-aging and photo-protective cosmetic applications. Of particular interest is the carotenoid phytoene, for its colorless and UV absorption characteristics. In this study, we targeted a reduction of phytoene desaturase (PDS) activity with the pigment-inhibiting herbicide 1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]pyridin-4-one (fluridone), which leads to the over-accumulation of phytoene in the recently characterized microalgal strain Chlorococcum sp. (UTEX B 3056). After post-incubation with fluridone, phytoene levels were measured at ~33 ug/mg cell tissue, as opposed to non-detectable levels in control cultures. Hence, the novel microalga Chlorococcum sp. is a viable candidate for the production of the high-value carotenoid phytoene and subsequent applications in cosmeceuticals, as well as more obvious nutraceutical and pharmaceutical applications

Preservation of Phenols, Antioxidant Activity, and Cyclic Adenosine Monophosphate in Jujube (<i>Ziziphus jujuba</i> Mill.) Fruits with Different Drying Methods

Jujube, commonly known as the Chinese date, is a nutritious fruit with medicinal importance. Fresh jujube fruits have a shelf life of about ten days in ambient conditions that can be extended by drying. However, nutrition preservation varies with the drying method and parameters selected. We studied total phenolic content (TPC), proanthocyanidins (PA), vitamin C, cyclic adenosine monophosphate (cAMP), and antioxidant activities in jujube fruits dried with freeze-drying (FD), convective oven drying (OD) at 50 °C, 60 °C, and 75 °C, and sun drying (SD) with FD as a control. The cultivars used for this study were ‘Capri’ and ‘Xiang’ from Las Cruces in 2019, and ‘Sugarcane’, ‘Lang’, and ‘Sherwood’ from Las Cruces and Los Lunas, New Mexico, in 2020. Freeze-drying had the highest of all nutrient components tested, the best estimates of mature jujube fruits’ nutrient contents. Compared with FD, the majority of PA (96–99%) and vitamin C (90–93%) was lost during SD or OD processes. The retention rates of antioxidant activities: DPPH and FRAP were higher in OD at 50/60 °C than SD. SD retained a higher cAMP level than OD at 50/60 °C in both years. The increase in oven drying temperature from 60 °C to 75 °C significantly decreased TPC, PA, antioxidant activities, and cAMP

Green microalgae cultured in textile wastewater for biomass generation and biodetoxification of heavy metals and chromogenic substances

Wastewater treatment is expensive and algae are increasingly tested for their usefulness in cleaning wastewater. Here, we evaluated six microalgae isolates for their ability to grow in textile wastewater. The sequences of the genes coding for the 18S, ITS 1 and ITS 2 regions placed all algae isolates in the Chlorellaceae family (green algae). Biomass was generated for each algae strain with textile wastewater diluted with deionized water and algal dry weight of 0.4–1.35 g L−1 was obtained. Elemental analyses of the wastewaters were carried out before and after cultivation of the algae strains and dye colour removal was also estimated. Supernatant obtained after biomass harvest showed reduction/removal of heavy metals like Al, Cu, V, Pb and Se. Chromogenic substances present in the textile wastewater were also reduced by 47.10–70.03% at a lambda max of 558 nm

Particulate sulfur-containing lipids: Production and cycling from the epipelagic to the abyssopelagic zone

There are major gaps in our understanding of the distribution and role of lipids in the open ocean especially with regard to sulfur-containing lipids (S-lipids). Here, we employ a powerful analytical approach based on high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to elucidate depth-related S-lipid production and molecular transformations in suspended particulate matter from the Northeast Atlantic Ocean in this depth range. We show that within the open-ocean environment S-lipids contribute up to 4.2% of the particulate organic carbon, and that up to 95% of these compounds have elemental compositions that do not match those found in the Nature Lipidomics Gateway database (termed “novel”). Among the remaining 5% of lipids that match the database, we find that sulphoquinovosyldiacylglycerol (SQDG) are efficiently removed while sinking through the mesopelagic zone. The relative abundance of other assigned lipids (sulphoquinovosylmonoacylglycerol (SQMG), sulfite and sulfate lipids, Vitamin D2 and D3 derivatives, and sphingolipids) did not change substantially with depth. The novel S-lipids, represented by hundreds of distinct elemental compositions (160–300 molecules at any one depth), contribute increasingly to the lipid and particulate organic matter pools with increased depth. Depth-related transformations cause (i) incomplete degradation/transformation of unsaturated S-lipids which leads to the depth-related accumulation of the refractory saturated compounds with reduced molecular weight (average 455 Da) and (ii) formation of highly unsaturated S-lipids (average abyssopelagic molecular double bond equivalents, DBE=7.8) with lower molecular weight (average 567 Da) than surface S-lipids (average 592 Da). A depth-related increase in molecular oxygen content is observed for all novel S-lipids and indicates that oxidation has a significant role in their transformation while (bio)hydrogenation possibly impacts the formation of saturated compounds. The instrumentation approach applied here represents a step change in our comprehension of marine S-lipid diversity and the potential role of these compounds in the oceanic carbon cycle. We describe a very much higher number of compounds than previously reported, albeit at the level of elemental composition and fold-change quantitation with depth, rather than isomeric confirmation and absolute quantitation of individual lipids. We emphasize that saturated S-lipids have the potential to transfer carbon from the upper ocean to depth and hence are significant vectors for carbon sequestration