Search

While astrocytes are known to be important for development and nourishment of the nervous system, the field is just beginning to explore how astrocytes respond to environmental stimuli. UsingCaenorhabditis elegansand their astrocyte-equivalent, CEPsh, we asked whether astrocyte-like glia respond to odor exposure. We found one day-old adultC. elegansdecreasehlh-17promoter (CEPsh glia marker) mediated fluorescent expression when trained with an innately attractive odor butanone. Moreover, the olfactory training paradigm itself affects phlh-17expression, but in a different way. This suggests astrocyte-like CEPsh glia can integrate environmental information to respond to changes in the environment, which enhances survival.

Insulin signaling has been implicated in many physiological processes, such as development, metabolism and stress survival, thereby ensuring an animal’s homeostasis. Thus, to enable the pathway to function with high precision, its ligands can undergo multiple levels of regulation—at the transcriptional, post-transcriptional and post-translational levels. Interestingly, we now find that the endogenous mRNA transcripts of the C. elegans insulin-like peptide ins-6 also become localized to specific structures. ins-6 transcripts are present in the axonal nerve ring of the stress-resistant dauer larva. In contrast, non-dauer and post-dauer larvae have ins-6 transcripts that are localized to the somas of the ASI and ASJ sensory neurons and not to the nerve ring. The absence of other neuronal mRNAs in the dauer axonal nerve ring suggests specificity in this mRNA localization of ins-6, which has previously been shown to be important during the switch to and from dauer physiology.

An animal’s responses to environmental cues are critical for its reproductive program. Thus, a mechanism that allows the animal to sense and adjust to its environment should make for a more efficient reproductive physiology. Here we demonstrate that in Caenorhabditis elegans specific sensory neurons influence onset of oogenesis through insulin signaling in response to food-derived cues. The chemosensory neurons ASJ modulate oogenesis onset through the insulin-like peptide (ILP) INS-6. In contrast, other sensory neurons, the olfactory neurons AWA, regulate food type-dependent differences in C. elegans fertilization rates, but not onset of oogenesis. This AWA effect is distinct from the effects of insulin receptor signaling, where the latter regulates fertilization independently of food type and requires ILPs other than INS-6. Together our findings suggest that optimal reproduction requires the integration of diverse food-derived inputs through multiple neuronal signals acting on the C. elegans germline.

Solitary fibrous tumor (SFT) is a benign spindle cell neoplasm of mesenchymal fibroblast cells. It can appear in various locations, but SFT of the lacrimal sac is rare. Due to their variable clinical, histological, and radiological presentation, it can be easily misdiagnosed. We report a rare case of SFT of the lacrimal sac with its radiological, histological, and immunochemical characterization.

Introduction Parathyroid crisis is a characterized by severe hypercalcemia associated with multiple organ dysfunction. Case 90 years-old Caucasian man was hospitalized for progressive confusion over 3 days and was noted to have a critically elevated serum calcium (S Ca) 16.8 mg/dl (8.6-10.0) with albumin 4.1 mg/dl. Patient had a good functional status prior to the hospitalization. On further evaluation, patient was diagnosed with primary hyperparathyroidism with a high suspicion for parathyroid cancer, with labs showing a markedly elevated PTH 1183 pg/ml (15-65) and ionized Ca >1.85 mmol/L (1.15-1.35). Of note, S Ca was normal at 9.5 mg/dl (no albumin) approximately 20 months prior to the hospitalization. Parathyroid ultrasound showed a 1.8×1.7×1.1 cm left superior parathyroid mass with ill-defined margins. Sestamibi scan confirmed a left superior parathyroid mass. CT neck/chest/abdomen/pelvis with contrast showed a 1.8×1.1×1.9 cm left superior parathyroid mass with enhancement and punctate non-obstructing right kidney stones. Hypercalcemia responded extremely well to medical management (calcitonin, 4 mg of zoledronic acid infusion and 13 days of cinacalcet 30 mg daily) resulting in normalization of S Ca. However, patient required a prolonged hospitalization for aspiration pneumonia and severe electrolyte disturbances. Since patient was not a good surgical candidate and hypercalcemia resolved on medical management, patient was discharged to a rehab facility with the plan to pursue parathyroidectomy as outpatient. S Ca worsened progressively and was 10.4 mg/dl (albumin 3.6 mg/dl) with PTH 130 pg/ml on day 15 after discharge. Cinacalcet was added when hypercalcemia further worsened to 11.7 mg/dl (albumin 3.6 mg/dl) on day 38. However, patient was hospitalized again for altered mental status, recurrent severe hypercalcemia (S Ca 15.7 mg/dl, albumin 3.8 mg/dl, PTH 1299 pg/ml), hypokalemia and urinary tract infection. In the ED, patient developed complete heart block that responded to atropine. Interestingly, hypercalcemia was recalcitrant to aggressive medical management during this hospitalization (zoledronic acid 4 mg infusion, calcitonin IM- increased up to 6 mg IM q6hr, cinacalcet- increased to 60 mg PO BID and IV fluid resuscitation with furosemide as needed). S Ca was 14.2 mg/dl (albumin 3.4 mg/dl) on day 8 of hospitalization. Therefore, urgent left superior parathyroidectomy was performed. Surgical pathology revealed a 3.1 gm parathyroid adenoma. Post-operative day#1 labs showed normal PTH 17.3 pg/ml, S Ca 12.1 mg/dl and albumin 3.2 mg/dl. S Ca and patient's mental status normalized over next few days. Discussion Urgent parathyroidectomy has shown to have excellent outcomes in patients with parathyroid crisis. Our patient's severe hypercalcemia initially responded excellently to medical management but recurred within few weeks and developed resistance to medical management. Our case highlights the importance of performing surgical exploration as soon as possible after initial medical stabilization in patients with parathyroid crisis. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

To study the effect of real time continuous glucose monitor (RT-CGM) use on glycemic parameters in patients with diabetes mellitus (DM) in real world practice.We retrospectively studied 91 adult subjects with DM who had been using Dexcom™ RT-CGM. Two consecutive hemoglobin A1c (HbA1c), both prior to and after at least 3 months of RT-CGM initiation, were collected. A total of 31 subjects completed a 5-14 day user blinded CGM using a Freestyle Libre™ prior to RT-CGM initiation. The first two week period following at least 3 months use of RT-CGM was analyzed for CGM metrics.A total of 51.6 % of subjects had T1DM, 34.1 % used continuous subcutaneous insulin infusion (CSII), and 62.6 % had DM for 10 years. Both HbA1c obtained following RT-CGM initiation decreased significantly compared to baseline (8.11 + 1.47% vs 7.69 + 1.25 %; P = 0.0028.16 + 1.51 % vs 7.62 + 1.06 %; P = 0.001). Subjects with baseline HbA1c 7.0 % showed even more robust reduction in both HbA1c after RT-CGM initiation (8.74 + 1.24 % vs 7.99 + 1.22 %; P = 0.0008.74 + 1.32 % vs 7.85 + 1.07 %; P = 0.001). On comparison of CGM metrics, there was a significant reduction in time spent in hypoglycemia (sugars70 mg/dl) including severe hypoglycemia (sugars54 mg/dl) after initiation of the RT-CGM (9.16 + 8.68 % vs 1.29 + 2.21 %; P = 0.0014.58 + 5.43 % vs 0.28 + 0.58 %; P = 0.001). CoV of glucose was also decreased significantly (39.61 + 9.36 % vs 31.06 + 6.74 %; P = 0.001) with RT- CGM use.RT-CGM use for at least 3 months in patients with DM results in meaningful HbA1c reductions with stable glycemic control without increasing the risk of hypoglycemia.

Aim Previous evidence suggests that some fields of cognitive function are man dominated while others are woman dominated. Recent research has additionally associated sexual orientation with cognitive function. However, data on the effect of sexual orientation on various cognitive subdomains are limited. We aim to explore the variability in a range of cognitive subdomains (working memory, language, attention, processing speed, and executive functioning) by cis-gender hetero versus homo sexual orientation. Methods We combined NHANES 2011–2012 and NHANES 2013–2014 datasets to study the individuals (60-69 years old) with both sexual health and cognitive assessment data. We analyzed the data to assess the performance of heterosexual and homosexual men and women on various cognitive function assessments. We used 1) word learning and recall modules from the Consortium to Establish a Registry for Alzheimer's disease (CERAD) to examine new verbal learning, immediate and delayed memory; 2) the Animal Fluency test (AFT) to evaluate verbal sematic fluency and 3) the Digital Symbol Substitution test (DSST) to assess attention and processing speed. Mentally impaired individuals or participants who were unable to understand or read English, Spanish, Korean, Vietnamese, traditional or simplified Mandarin, or Cantonese were not asked questions regarding sexual orientation and hence, were excluded from final analysis. Simple Linear regression models were used to quantify the association of sexual orientation and cognitive function. Statistical significant was specified at P < 0.05. Results Our study population consists of 61 homosexual adults (39 men and 22 women) and 3087 heterosexual adults (1486 men and 1601 women). Comparison of heterosexual men and women demonstrated differences typically found between the genders, with heterosexual women performing significantly better on all cognitive function assessments. Homosexual men scored significantly higher than heterosexual men on all cognitive function assessments and performed in the direction of heterosexual women in all cognitive domains. In fact, mean scores for homosexual men were even higher than for heterosexual women in the four of the six cognitive domains tested (CERAD 2 and delayed recall, AFT and DSST). Homosexual women did not differ from heterosexual women and homosexual men on any of the measures of cognitive performance. Therefore, as expected, homosexual women scored higher points than heterosexual men on most cognitive assessments (CERAD 1,3 and delayed recall, and DSST). Conclusion Homosexual men were gender-atypical and performed in the direction of heterosexual women in cognitive domains related to working memory, language, attention, processing speed, and executive functioning. Homosexual women were sex-typical with cognitive skills similar to heterosexual women. These findings underscore the need for further studies to understand the association of sexual orientation with cognitive functioning. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Methane-based membrane biofilm reactors (MBfRs) can be an effective solution for nitrogen control in wastewater, but there is limited information on nitrite reduction for dilute wastewater (e.g., municipal wastewater) in hypoxic MBfRs. This study assessed the impacts of dilute (20 %), low-pressure methane (0.35-2.41 kPa) applied to MBfRs at hydraulic retention times (HRTs) of 2-12 h on nitrite removals, dissolved methane concentrations, and the resulting changes in the microbial community. High nitrite flux along with rapid and virtually complete (99 %) nitrite removals were observed at methane pressures of 1.03-2.41 kPa at HRTs above 4 h, despite the use of diluted methane gas for the MBfR. The lowest methane pressure (0.35 kPa) was also able to achieve up to 98 % nitrite removals but required HRTs of up to 12 h. All scenarios had low dissolved methane concentrations (10 mg/L), indicating that dilute methane at low supply pressures can effectively remove nitrite while meeting dissolved methane guidelines in treated effluent. Methylococcus genus was the key bacterium in MBfR biofilm grown at different HRTs and methane pressures, along with Methylocystis and other heterotrophic denitrifiers (Terrimonas and Hyphomicrobium). This study indicates that methane-based denitrification MBfRs can be a valuable tool to meet nitrogen limits for dilute wastewater coupled to partial nitrification, while limiting the release of methane to the environment.

Background Recently thyroid hormone studies on brain growth, development and activity are regaining popularity. Thyroid hormones have long been believed to play critical role in mammalian brain growth and maturation regulating facets of neuronal cell growth, proliferation and differentiation and further signaling and glial cell differentiation. Deficiency of these hormones in mother leads to mental retardation in the subsequent offspring's. Methods In this presented study, brain development of iodine deficient rat models created through deficiency in feeding, mating and further selection. Young adult female wistar rats were induced with iodine deficiency and then mated with healthy male rats. These pregnant hypothyroid induced females were treated with β-sitosterol (150 mg/kg/day) and quercetin (150 mg/kg/day) alone and in combination for whole gestation period. Analysis were dealt with the genetic and histological studies of the pups brain. PCR based RNA analysis was also carried out. Histology was done using eosin and hematoxylin. Results Positive impacts of the β-sitosterol and quercetin on the iodine deficient brain were observed upon histological and PCR analysis. Altogether, the analysis proves that combined doses of β-sitosterol and quercetin for normal brain development in iodine deficient infants hence can be potentially applied as therapeutics in iodine deficiency circumstances.

Memory, defined as an alteration in behavior towards a stimulus that follows as a consequence of experience, arises when a sensory stimulus is encountered at the same time that the animal experiences a negative or positive internal state. How this coincident detection of external and internal stimuli stably alters responses to the external stimulus is still not fully understood, especially in the context of an intact animal. One barrier to understanding how an intact biological circuit changes is knowing what molecular processes are required to establish and maintain the memory. The optically accessible and compact nervous system ofC. elegansprovides a unique opportunity to examine these processes.C. eleganscan remember an odor such as butanone when it is paired with a single negative experience and the transient receptor potential (TRP) OSM-9/TRPV5/TRPV6 channel is known to be required for this memory. The multiple gating mechanisms of TRPV channels give them the potential to be the coincidence detectors required to integrate internal state and external stimuli. Here, we report that this TRPV channel is also required for acquisition and possibly consolidation of sleep-dependent, long-term memory of butanone. We find that in the anterior ganglion, endogenous GFP-tagged OSM-9 is expressed in the paired AWA olfactory neurons, the ASH nociceptive neuron pair, the mechanosensory OLQ tetrad, and the paired ADF and ADL sensory neurons. In these cells, OSM-9 protein is concentrated in the sensory endings, dendrites, and cell bodies, but excluded from the neurites in the nerve ring. In the tail, OSM-9 is expressed in the nociceptive phasmid neurons PHA and PHB, possibly PQR as well as PVP. In the midbody, it is possibly expressed in the mechanosensitive PVD neuron. It is notably absent from the AWC pair that are required for butanone attraction. Chronic loss of OSM-9 in a subset of ciliated neurons that do not include AWA interferes with consolidation but not learning. Because OSM-9 is expressed and required in sensory neurons that are not needed for butanone chemosensory behavior, two interpretations are possible. The first, is that OSM-9 loss leads to gain of function or neomorphic behavior of these cells that are extrinsic to the primary sensory circuit and their new activity interferes with acquisition and consolidation of memory. The second is that loss of OSM-9 leads to a loss of function phenotype in which the wild type function of these cells is diminished and this function is required for memory consolidation.Author summaryHow organisms learn from their environment and keep these memories for the long term ensures their survival. There is much known about the regions of the brain and the various proteins that are essential for memory, yet the exact molecular mechanisms and dynamics required are not known. We aimed to understand the genetics that underlie memory formation. We tested a gene that encodes a transient potential receptor channel vanilloid channel, which is similar to the channels we have that sense spicy foods and other harmful cues. Our studies have shown that this gene is required for the animal to be able to acquire and perhaps consolidate olfactory memory. This protein is not expressed in the sensory neurons that respond to the odor that is memorized or in other downstream interneurons in the odor-sensation circuit, but it is expressed in a distinct set of sensory neurons. This indicates that long-term memory involves wild type behavior of a wider array of sensory neurons than is required for the primary sensation. These channels are also implicated in neurological disorders where memory is affected, including Alzheimer’s disease. Understanding how memory formation is affected by cells outside the memory circuit might provide testable hypothesis about what goes awry in Alzheimer’s disease.

SUMMARYAnimals with complex nervous systems demand sleep for memory consolidation and synaptic remodeling. Here we show that though theCaenorhabditis elegansnervous system has a limited number of neurons, sleep is necessary for both processes. In addition, it is unclear in any system if sleep collaborates with experience to alter synapses between specific neurons and whether this ultimately affects behavior.C. elegansneurons have defined connections and well-described contributions to behavior. We show that spaced odor-training and post-training sleep induce long-term memory. Memory consolidation, but not acquisition, requires a pair of interneurons, the AIYs, which play a role in odor-seeking behavior. In worms that consolidate memory, both sleep and odor conditioning are required to diminish inhibitory synaptic connections between the AWC chemosensory neurons and the AIYs. Thus, we demonstrate in a living organism that sleep is required for events immediately after training that drive memory consolidation and alter synaptic structures.

We report a case of avascular necrosis (AVN), hypercalcemia, and iatrogenic Cushing’s syndrome in an HIV-positive patient taking inhaled (ICS) and nasal corticosteroids fluticasone and ritonavir. A 45-year-old HIV-infected African-American woman was seen for initial evaluation for multinodular goiter in December 2015. Relevant medications were ritonavir, raltegravir, darunavir, fluticasone propionate HFA, and nasal fluticasone propionate. Physical examination revealed classical cushingoid appearance but laboratory testing showed abnormal adrenocorticotropic hormone (ACTH) stimulation test. A diagnosis of iatrogenic Cushing’s syndrome due to inhibition of fluticasone metabolism from protease inhibitor (PI) therapy with secondary adrenal suppression was made. Fluticasone nasal spray and HFA were discontinued and hydrocortisone replacement dose was initiated. The patient’s Cushing’s related symptoms improved over several months. Follow-up evaluation showed non-parathyroid hormone-mediated hypercalcemia. A detailed laboratory evaluation looking for the etiology for hypercalcemia was unremarkable except for an elevated urine N-telopeptide/creatinine ratio. Meanwhile, the patient developed a new symptom of hip pain. MRI of both hips showed bilateral AVN. Sickle cell screen was negative and a right hip replacement was completed in May 2017. Since this is the fourth case report of AVN from iatrogenic Cushing’s syndrome in an HIV-infected patient taking a PI and ICS concomitantly, there is more likely a causal relationship and not simply a coincidental finding. Extreme caution should be used when considering any ICS therapy in combination with PIs in HIV-infected patients.

Aim To compare zinc (Zn) and copper (Cu) levels in US adults with normoglycemia, prediabetes and diabetes, and study the association of serum Zn and Cu levels with pancreatic β cell insulin secretion, pancreatic dysfunction and insulin resistance in US adults with normoglycemia and prediabetes. Method Homeostatic Model Assessment (HOMA2) calculator was used to compute estimates of steady state β cell insulin secretion (HOMA2-B), peripheral insulin sensitivity (HOMA2-S), insulin resistance (HOMA-IR), and disposition index (HOMA-DI) in 804 adult individuals from the National Health and Nutrition Examination Survey (NHANES 2011–2012). Results There was no significant difference between serum Zn and Cu levels among subjects with normoglycemia, prediabetes, and diabetes. After adjusting for multiple possible confounders, higher serum Zn concentrations were associated with lower β cell insulin secretion (HOMA2-B; p = 0.01) and lower insulin resistance (HOMA-IR; p = 0.04) in the prediabetic subjects. In normoglycemic group, higher serum Zn levels were associated with improved pancreatic function (HOMA-DI; P = 0.02). On the other hand, higher serum Cu levels were associated with increased β cell insulin secretion (HOMA2-B, P = 0.03) only in the subjects with prediabetes. Conclusion These findings support the need for further studies to investigate the role of trace elements in diabetes pathogenesis.

Microbial electrochemical cells (MEC) constitute an emerging technology between electrochemistry and microbiology. MEC have been designed for various product recovery and reduction of oxidized contaminants. They are based on the bacterial interaction with insoluble electron acceptors, relying on the exchange of metabolic electron removed e-donor or supplied to the electrode. In this chapter, we will discuss the cathodic H2 production and the removal of oxidized contaminates in MEC.

Cyanobacteria and microalgae have the ability to convert sunlight and convert carbon dioxide (CO2) photosynthetically to biofuel like hydrogen, biodiesel, and value-added compounds. They have unique compositions of saturated fatty acid for providing good fuel quality. Their metabolic versatility helps them to grow in various nutritional environments. However, bioprocess scale-up remains a bottleneck in commercializing these technologies. Modes of cultivation are of major importance for upscaling and generating huge amounts of biomass with the required fuel properties. Different bioreactor designs have been explored for the cultivation of microalgae and cyanobacteria by fusing the required conditions of biomass productivity and environmental sustainability. For economical biomass production, different bioreactor configuration strategies have been discussed in this chapter. This chapter reflects on the current state of photosynthetic biomass cultivation toward biodiesel production and carbon footprint reduction.

Cardiovascular disease (CVD) in the diabetic patient is both widespread and fatal in nature. In the United States, roughly two-thirds of deaths in diabetic patients are due to CVD. In addition to the increased morbidity and mortality of CVD in a patient with diabetes, the impact of this comorbidity on health care expenditure is staggering. Unfortunately, researches on the effects of strict glycemic control on cardiovascular (CV) events have been unable to demonstrate a conclusive benefit, despite improvement for microvascular complications. Newer glycemic agents, specifically the glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium-glucose cotransporter-2 (SGLT-2) inhibitors, have shown much more promising cardioprotective properties, and are valuable as an add-on therapy for patients who do not reach their hemoglobin A1c goal on metformin alone. Most of the drugs in GLP-1 RA and SGLT-2 inhibitor class have shown strong cardioprotective effects in well-designed cardiovascular outcome trials and all of them have demonstrated CV safety. Multiple SGLT-2 inhibitors have shown renal protective effects as well as prevent hospitalization for heart failure and hence, should be preferred over GLP-1 RAs in patients with concurrent T2DM and heart failure or CKD.

Nowadays, dairy waste represents a global challenge as a result of the amount produced worldwide. Initially, one of the major objectives was to transform this waste into a single valuable product, but recently the concept of biorefinery has been applied to convert dairy waste into several valuable bioproducts such as biofuels, feed additives, bioplastics, and chemicals. Despite the potential that represents this kind of waste for the production of bioproducts, it is not a technology used extensively. An important factor that can help to become the biorefinery of dairy waste more attractive is the measure of the biorefinery complexity index (BCI). The BCI is a measure of the technological and economic risk to develop a biorefinery process using specific raw materials, production, extraction and purification processes. Our analysis of a dairy biorefinery gives a BCI of 20, which reflects a sustainable biorefinery. The dairy biorefinery synergistic approach predicted presents a zero-waste generation in the dairy industry. This will provide strength in academic and industrial level towards a biorefinery process design.

2,4,6-trinitrotoluene (TNT) and its derivatives are nitrogen-containing aromatic compounds having chemical and thermal stability at ambient temperature and pressure. TNT has high toxicity and mutagenic activity to humans, plants and animals, thus decontamination processes are necessary. Many microorganisms are capable to bioremediate TNT such as bacteria from the genera Pseudomonas, Enterobacter, Rhodococcus, Mycobacterium, Clostridium and Desulfovibrio; fungus such as Phanerochate and Stropharia species are able to perform TNT biotransformation under aerobic and anaerobic conditions. In this work we review the state of TNT biodegradation by various routes: aerobic, anaerobic, combined, fungal, enzymatic, and bio-electrochemical. Keywords: Laccases, Aerobic degradation, Anaerobic degradation, Fungal TNT degradation

With objective to design cyanobacterial biorefinery, taking Lyngbya as a model organism, a detail sequential protocol has been developed for production of UV protectant and lipids. This study addresses ultra violet radiations (UVR), exposure time of UVRT, nitrogen stress, salinity, oxidative stress to produce UV protectant and lipid in cyanobacteria. To evaluate these parameters a design of experiment (DOE; using a 2 k design) was performed. Based on chemical solubility property of UV protectant in form of mycosporine like amino acid (MAAs) and lipids were extracted. Quantitative and qualitative assay of UV protectant was confirmed by spectrophotometric scanning and Fourier-transform infrared spectroscopy and lipid through fatty acid methyl esters analysis. Nitrogen abundance and high oxidative stress is helpful in the synthesis of UV protectant. This study concluded, UV exposure is good strategy to induce synthesis of UV protectant and saturated lipid productivity. This biorefinery approach encourages economical and environmentally sustainable options. The authors want to thank the Director of the School of Engineering and Science, Tecnologico de Monterrey , for his encouragement and financial support. Rashmi Chandra wants to thank Conacyte for proving support in form of SNI-C (CVU No. 739144). Scopus

This article documents the synergetic interaction between oxygenic photosynthesis (microalgae; cathode) and anoxygenic photosynthesis (photosynthetic bacteria; anode) toward bioenergy and biomass generation apart from wastewater treatment using a dual chambered biophotovoltaic cell. Microalgae as the biocathode negate the requirement of an external terminal electron acceptor as they can be efficient in situ oxygenators that facilitate the oxygen reduction reactions. Experiments were performed in a fed batch mode using designed synthetic wastewater at variable organic loading rates in the anodic chamber and domestic sewage as feed in the cathodic chamber with a retention time of 72 h. Operation at OL3 (1500 mg/L) showed maximum power output (0.7 V; 103 mW/m2). Anodic chamber showed a maximum substrate (COD) degradation efficiency of 81%, while the cathode showed a constant COD removal efficiency of 90%. Maximum microalgal lipid productivity of 20% was observed at OL4 and OL5. The designed biophotovoltaic c...

The detection of new pollutants, stricter environmental regulations, and advancements in treatment technologies are driving improvements in bioprocesses for treating wastewater. Specifically, special concern is being placed on phosphorus and nitrogen forms, which spur eutrophication of water bodies, and emerging micropollutants such as pharmaceuticals and person-care products. Algae and cyanobacteria cultivation requirements include water and nutrient sources that currently are supplied by fertilizers, which provide poor sustainability and economics. Using wastewater as a source of nitrogen and phosphorus represents an attractive option to cultivate microalgae simultaneous with contaminant removal. Phycoremediation refers to the assimilation or disintegration of organic and inorganic compounds (carbon, nitrogen, or phosphorus), metals, and emerging contaminants in wastewater by microalgae – algae and cyanobacteria. In addition, added value comes when the microalgae are harvested to become feedstock for biofuels such as biogas. Although promising studies have been published for algal growth in wastewater while simultaneously removing contaminants, limitations in the scale-up process still have to be addressed. In this work, we summarize biological mechanisms by which nutrients and contaminants are removed by microalgae. We specifically address the interactions that the microalgae have with other microorganisms and the production of extracellular polymeric substances, a mechanism well known in the literature, but hardly studied in microalgae. Finally, we discuss different strategies reported to improve the scale up of microalgae cultivation in wastewater.

Bioactivity and functional properties of cyanobacterial extract mostly depends on process of extraction, temperature and solvent used (polar or non-polar). To evaluate these parameters a design of experiment (DOE; using a 2k design) was performed with Arthrospira platensis. Extraction process was optimized through microwave-assisted extraction considering solvent ratio, temperature and time of extraction with polar (PS) and non-polar (NPS). Maximum extract yield obtained was 4.32±0.25% and 5.26±0.11% (w/w) respectively for PS and NPS. Maximum content of bioactive metabolites in PS extracts were thiamine (846.57±14.12μg/g), riboflavin (101.09±1.63μg/g), C-phycocyanin (2.28±0.10μg/g) and A-phycocyanin (4.11±0.03μg/g), while for NPS extracts were α-tocopherol (37.86±0.78μg/g), β-carotene (123.64±1.45μg/g) and 19.44±0.21mg/g of fatty acids. A. platensis PS extracts showed high antimicrobial activity and PS extracts had antioxidant activity of 0.79±0.12μmolTE/g for FRAP assay, while for NPS extracts 1.03±0.08μmol α-TE/g for FRAP assay.

This chapter focuses on renewable power generation approaches based on the coupling of photosynthetic bioreactors. In PhFCs, oxidation of organic compounds results in electrons production by photosynthetic bacteria. PhFC research has allowed the generation of a wide variety of different system configurations, the use of photosynthetic mechanism, and respective organisms. Oxygenic photosynthetic species commence charge separation results in delivering electrons and protons in a photophosphorylation cascade. Photosynthetic microbial fuel cell research started with cyanobacterial species of Synechocystis and Anabaena by documenting the increment in power output in light and decrement in power during the dark. Photosynthetic organisms use carbon dioxide as carbon source, and photosynthetic reactions involve the reduction of this molecule. Oxygen generation in photosynthetic reactions represents an interesting characteristic in the cathode process, because mechanic aeration requires vast quantities of energy. Illumination is a salient feature for growth of photosynthetic microorganisms.

The treatment of nitrogen-deficient agriculture wastewater, arising from the vegetable and fruit processing, is a significant problem that limits the efficiency of its biological treatment. This study evaluates the effectiveness of the symbiotic co-culture of Azospirillum brasilense and Scenedesmus sp., under two nitrogen levels (8.23 mg L&minus, 1 and 41.17 mg L&minus, 1) and mixing systems (aeration and magnetic stirring), aiming to simultaneously use the N-deficient media for their growth while producing biomass for biofuels. Microalgae growth and biomass composition, in terms of protein, carbohydrate and fatty acid contents, were evaluated at the end of the exponential growth phase (15 days after inoculation). Results show that the symbiotic co-culture of microalgae-bacteria can be effectively performed on nitrogen-deficient media and has the potential to enhance microalgae colony size and the fatty acid content of biomass for biofuels. The highest biomass concentration (103 &plusmn, 2 mg&middot, L&minus, 1) was obtained under aeration, with low nitrogen concentration, in the presence of A. brasilense. In particular, aeration contributed to, on average, a higher fatty acid content (48 &plusmn, 7% dry weight (DW)) and higher colony size (164 &plusmn, 21 &micro, m2) than mechanical stirring (with 39 &plusmn, 2% DW and 134 &plusmn, m2, respectively) because aeration contribute to better mass transfer of gases in the culture. Also, co-culturing contributed in average, to higher colony size (155 &plusmn, m2) than without A. brasilense (143 &plusmn, m2). Moreover, using nitrogen deficient wastewater as the culture media can contribute to decrease nitrogen and energy inputs. Additionally, A. brasilense is approved and already extensively used in agriculture and wastewater treatment, without known environmental or health issues, simplifying the biomass processing for the desired application.

Microalgae have the intrinsic ability to harness energy from sunlight and photosynthetically valorize CO2 into fuel molecules, which can further be converted to biodiesel. They have a unique profile of fatty acids comprising of a mixture of saturated and unsaturated fatty acids. Microalgae have adapted to grow in various nutritional environments due to their metabolic versatility and resilience. Cultivation systems are of major importance for upscaling and generating large amounts of biomass with fuel properties. Novel photobioreactor designs have recently been explored for integration with urban infrastructure by fusion of principles of urban ecology and environmental sustainability. High throughput techniques for estimation of biodiesel quality have made analysis simpler and more reliable. For economical production of biomass, integrating biodiesel production with industrial flue gases and wastewater treatment is considered a viable strategy in algal cultivation. This chapter sheds light on the current state of art in algal cultivation for biomass and enhancing the lipid profile towards biodiesel production thus reducing carbon footprints.

Recently developed technologies of photosynthetic microbial fuel cells (PhFCs) that utilize solar energy to produce electricity have gained important interest in basic and applied research due to their sustainable and renewable nature. Photosynthetic microbes have been studied in diverse reactor configurations to understand the mechanism of their operation. Besides power generation, PhFCs have a potential to treat wastewater along with the production of diverse value-added products such as biohydrogen and lipids, among others, through a biochemical process. The potential uses of this technology are part of the domain of environmental engineering and bioremediation, and the involvement of multiple disciplines. This chapter explores the state of art of PhFC systems for efficient utilization of photosynthetic mechanisms for product recovery, wastewater treatment and pertaining mechanisms.

Microalgae are regarded as a promising and feasible source of diverse products for application in the nutraceutical, pharmaceutical, cosmeceutical, and chemical industries. Such products include biofuels, lipids, polyunsaturated fatty acids, pigments, enzymes, polysaccharides, and proteins. The recovery of products from algal biomass is a matter of constant development and progress. In the present chapter, the standard techniques for the extraction of biofuels and high-value metabolites from microalgae in the laboratory are reviewed. Traditional methods such as solvent extraction, as well as novel techniques, like supercritical fluid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are presented in this work, including the suitability of these methods for specific types of metabolites. Pretreatment techniques for the enhancement of product recovery are discussed. This chapter is intended as a reference of the existing methods for the researcher looking forward to study the production of metabolites by microalgae, in order to aid the selection of a suitable technique for specific metabolites.

We evaluated cost-effective food waste (FW) treatment and synthesis of volatile fatty acids (VFA) using a leach bed reactor (LBR) operated at neutral pH and room temperature to maximize the profit from recovered products. Three inoculation strategies that include (1) inoculum pretreatment, (2) pretreatment plus leachate recycle, and (3) sole leachate recycle were examined and LBR performance was compared in these inoculation conditions. The inoculation method influenced the hydrolysis of FW in the LBR. Hydrolysis yield was as high as 771 ± 4 g cum.sCOD/kg VSadded with the second inoculation method only in a short reaction time of 6 d. Butyric and acetic acids consistently dominated VFA, and the LBR achieved the highest VFA yield of 649 ± 13 g COD/kg VSadded in the second inoculation. Bacterial community dynamics targeting 16S rRNA gene suggested that Roseburia would be the key player to fermentation of slowly biodegradable FW (e.g., fibers), while multiple types of bacteria affiliated with Enterobacteriaceae, Lactococcus, and Bacteroides mainly fermented FW to butyric and acetic acids at initial phase. The operating cost for FW treatment was calculated $88.1-$126.8 per ton of VSadded in the LBR. This study suggests that LBRs can economically stabilize FW only in 6 d without regular inoculation of exogenous microorganisms, along with high VFA recovery.

Cyanobacteria can have high lipid content, are amenable to metabolic engineering, and contain valuable materials, such as ultraviolet (UV) protectants and antioxidants. Maximizing the production and harvesting of several valuable products at the same time is an important objective. UV exposure was evaluated as a strategy to induce synthesis of UV protectants, higher lipid productivity, and a high lipid-saturation index in the cyanobacterium Lyngbya purpurem UTEX LB 2716. While UVA stimulated the highest production of lipids and the largest amount of mycosporine-like amino acids (MAAs), UVB lead to greater generation of MAAs, which correlated to higher antioxidant activity. UVB also showed a shift towards saturated fatty acids, such as C16:0 and C18:0, over unsaturated fatty acids, whereas UVA showed a shift towards the unsaturated fatty acids. In summary, UVB induced the highest MAAs production, anti-oxidant activity, and lipid saturation, and its yield of crude lipids and extracted FAME was only slightly lower than with UVA.

In recent years, ever-increasing socio-economic awareness, and negative impact of excessive petro consumption have redirected the research interests towards bio-resources such as algal-based biomass. In order to meet current bio-economy challenges to produce high-value multiple products at a time, new integrated processes in research and development are necessary. Though various strategies have been posited for conversion of algal-based biomass to fuel and fine chemicals, none of them has been proved as economically viable and energetically feasible. Therefore, a range of other bio-products needs to be pursued. In this context, the algal bio-refinery concept has appeared with notable solution to recover multiple products from a single operation process. Herein, an algal-based bio-refinery platform for fuel, food, and pharmaceuticals considering Bio-refinery Complexity Index (BCI) has been evaluated, as an indicator of techno-economic risks. This review presents recent developments on algal-biomass utilization for various value-added products as part of an integrated bio-refinery.

Solar radiation led into the planet earth by photosynthesis is the main energy basis for survival. Photosynthesis is a physico-chemical process where photosynthetic organism transform solar energy into chemical energy with simultaneous use of bioenergetic processes (Georgianna and Mayfield 2012; Strik et al. 2011). Photosynthetic microbial fuel cells (PhFCs) are newly established tools that harvest sun energy to yield electricity and has gained major attentiveness in applied and academic research due to its sustainable and renewable nature (Chandra et al. 2012; Venkata Mohan et al. 2014). PhFCs use plants or phototrophic microorganisms to trap sun light and use photo-bioelectrochemical system to produce bioelectricity (El Mekawy et al. 2014). This technology symbolizes a multi-disciplinary method to search for renewable energy. It represents the convergence for the life-sciences, chemical and physical science (McCormick et al. 2015; Xiao and He 2014). Microbial fuel cells (MFCs) are mainly focused towards anodic reaction with dark fermentation as microbial metabolic function. Analogous to dark fermentation, photosynthetic fuel cells (PhFC) or biophotovoltaic system (BPV) will also be functioned using photo synthetic bacteria (PSB) or algae/cyanobacteria based on their photosynthetic mechanism (oxygenic or anoxygenic) (Chandra et al. 2012; Rosenbaum et al. 2010a). Oxygenic photosynthesis based autotrophic PhFCs include diverse categories of MFC containing both heterotrophs and autotrophs (Venkata Mohan et al. 2010a, b, 2011) (Fig. 19.1). The current chapter has made an attempt to convey the present photosynthetic mechanism for PhFC application in understanding on the innate potential of photosynthetic mechanism.

Decarboxylation of short chain carboxylic acids or volatile fatty acids (VFA) for bioelectricity generation was explored using mixed photosynthetic bacteria (PSB) as biocatalyst in a single chambered photo-bioelectrocatalytic system (PBES)/biophotovoltaic system. Acetate rich wastewater (ARW) and butyrate rich wastewater (BRW) were synthetically prepared to be used as substrates for the comparative evaluation of photo bacteria catalyzed decarboxylation towards bioelectrogenic ability. Bioelectrogenic activity in terms of open circuit voltage, current and power density in ARW (605 mV; 2.14 mA; 112.20 mW m −2 ) was 55% higher than that of BRW (208 mV; 0.49 mA; 10.50 mW m −2 ). The first-derivative of cyclic voltammograms (DCV) also depicted the role of redox shuttles viz., Cytochrome-b and NADPH as electron carriers, detected as peaks in ARW operation in enhancing the performance of PBES. In addition, the phylogenetic inventory illustrated the dominance of proteobacteria such as Rhodopseudomonas sp. and Thiorhodovibrio sp. including N 2 fixers ( Amoebobacter sp.), which are the potent bio-electrogens. Anoxygenic photosynthesis by purple non sulfur bacteria has the potential for the treatment of acidogenic effluents from biohydrogen reactor with simultaneous yield of reducing equivalents for power generation. The integration of PBES with conventional biohydrogen production by dark fermentation has a potential application in the field of acidogenic waste valorization which is in concurrence with the concept of biorefinery.

Critical influence of different short chain fatty acids as organic carbon source, during growth (GP) and nutrient stress lipogenic phase (NSLP) was investigated on biomass and lipid productivity, in mixotrophic fed-batch microalgae cultivation. Nutrient deprivation induced physiological stress stimulated highest lipid productivity with acetate (total/neutral lipids, 35/17) with saturation index of 80.53% by the end of NSLP followed by butyrate (12/7%; 78%). Biomass growth followed the order of acetate (2.23 g/l) >butyrate (0.99 g/l) >propionate (0.77 g/l). VFA removal (as COD) was maximum with acetate (87%) followed by butyrate (55.09%) and propionate (10.60%). Palmitic acid was the most dominant fatty acid found in the fatty acid composition of all variants and butyrate fed system yielded a maximum of 44% palmitic acid. Protein profiling illustrated prominence of acetyl CoA-synthetase activity in acetate system. Thus, fatty acids provide a promising alternative feedstock for biodiesel production with integrated microalgae-biorefinery.

Microalgae are inexhaustible feedstock for synthesis of biodiesel rich in polyunsaturated fatty acids (PUFA) and valuable bioactive compounds. Their cultivation is critical in sustaining the global economy in terms of human consumption of food and fuel. When compared to autotrophic cultivation, heterotrophic systems are more suitable for producing high cell densities of microalgae for accumulation of large quantities of lipids (triacylglycerols) which can be converted into biodiesel. Consorted efforts are made in this communication to converge recent literature on heterotrophic cultivation systems with simultaneous wastewater treatment and algal oil production. Challenges faced during large scale production and limiting factors which hinder the microalgae growth are enumerated. A strategic deployment of integrated closed loop biorefinery concept with multi-product recovery is proposed to exploit the full potential of algal systems. Sustainable algae cultivation is essential to produce biofuels leading to green future.

Parkinson’s disease (PD) is a progressive neurodegenerative disease with devastating clinical manifestations. In PD, neuronal death is associated with intracellular aggregates of the neuronal protein α-synuclein known as Lewy bodies. Although the cause of sporadic PD is not well understood, abundant clinical and pathological evidence show that misfolded α-synuclein is found in enteric nerves before it appears in the brain. This suggests a model in which PD pathology originates in the gut and spreads to the central nervous system via cell-to-cell prion-like propagation, such that transfer of misfolded α-synuclein initiates misfolding of native α-synuclein in recipient cells. We recently discovered that enteroendocrine cells (EECs), which are part of the gut epithelium and directly face the gut lumen, also possess many neuron-like properties and connect to enteric nerves. In this report, we demonstrate that α-synuclein is expressed in the EEC line, STC-1, and native EECs of mouse and human intestine. Furthermore, α-synuclein–containing EECs directly connect to α-synuclein–containing nerves, forming a neural circuit between the gut and the nervous system in which toxins or other environmental influences in the gut lumen could affect α-synuclein folding in the EECs, thereby beginning a process by which misfolded α-synuclein could propagate from the gut epithelium to the brain.