Some peculiarities of the population biology of the ghost shrimp Nihonotrypaea petalura (Stimpson, 1860) (Decapoda: Callianassidae) in coastal waters of Vostok bay, the Sea of Japan

In June 2012, some features of the population biology of the ghost shrimp Nihonotrypaea petalura were studied first for the Russian waters in sublittoral populations of the Vostok Bay (Peter the Great Bay, Sea of Japan). It was found that N. petalura formed aggregations of an average density of 9–19 ind./m² at the depth of 0.2–3 m on rocky and mixed bottoms. The biomass of the aggregations was 15–27 g/m² or 1–33% of the average total biomass of macrozoobenthos, which included animals of 48 taxa. The maximum depth of the shrimp burrows was 52 cm. The populations consisted of animals with body lengths of 17–63 mm. In the size-frequency distribution, two peaks in the number, attributed to the shrimps of 24–29 and 39–48 mm size groups, were observed. The ratio of males to females almost did not vary with size and remained in general close to 1: 0.9 for the surveyed shrimp populations. The local differences in the studied parameters of N. petalura from the Vostok Bay, as well as from other areas of the range, are discussed in relation to features of the habitation of these animals that living in different biotopes.     

Isolation and Molecular Identification of Bacteria with Magnesite Enrichment Potential from Turanocak and Ortaocak Quarries in Kütahya-Turkey

Abstract

In this study, bacteria were isolated from two different magnesite quarries in Turanocak and Ortaocak mine in Kütahya-Eski?ehir region, one of the largest processed magnesite reserves in Turkey. The obtained isolates have a potential to solve important magnesite pollutant CaCO₃ but incapable to solve magnesium that has the most crucial role in the industry. Thus, potential bacteria were identified to be used for magnesite enrichment studies. The obtained isolates were identified and characterized according to the morphological, physiological, biochemical, and molecular techniques (16S rDNA PCR). According to the gene sequencing analysis Bacillus genus bacteria have the ability to solve CaCO₃. The data of the 16S rDNA gene sequence showed that there were 13 active strains grouped in Bacillus. These active strains; Bacillus sp (3), Bacillus atrophaeus (2), Bacillus thuringiensis (1), Bacillus circulans (1), Bacillus simplex (3), Bacillus endophyticus (1) Bacillus drentensis (1) and Bacillus idriensis (1).     

Dynamics of memory T cell proliferation under conditions of heterologous immunity and bystander stimulation

By examining adoptively transferred CSFE-labeled lymphocytic choriomeningitis virus (LCMV)-immune donor T cells in Thy-1 congenic hosts inoculated with viruses or with the cytokine inducer poly(I:C), strikingly different responses of bona fide memory T cells were found in response to different stimuli. Poly(I:C) (cytokine) stimulation caused a limited synchronized division of memory CD8 T cells specific to each of five LCMV epitopes, with no increase and sometimes a loss in number, and no change in their epitope hierarchy. Homologous LCMV infection caused more than seven divisions of T cells specific for each epitope, with dramatic increases in number and minor changes in hierarchy. Infections with the heterologous viruses Pichinde and vaccinia (VV) caused more than seven divisions and increases in number of T cells specific to some putatively cross-reactive but not other epitopes and resulted in substantial changes in the hierarchy of the LCMV-specific T cells. Hence, there can be memory T cell division without proliferation (i.e., increase in cell number) in the absence of Ag and division with proliferation in the presence of Ag from homologous or heterologous viruses. Heterologous protective immunity between viruses is not necessarily reciprocal, given that LCMV protects against VV but VV does not protect against LCMV. VV elicited proliferation of LCMV-induced CD8 and CD4 T cells, whereas LCMV did not elicit proliferation of VV-induced T cells. Thus, depending on the pathogen and the sequence of infection, a heterologous agent may selectively stimulate the memory pool in patterns consistent with heterologous immunity.     

Expression of pituitary adenylate cyclase-activating polypeptide and PACAP type 1 receptor in the rat gastric and colonic myenteric neurons

Pituitary adenylate cyclase-activating polypeptide (PACAP) is known to regulate gastric acid secretion and intestinal motility. In the present study, the pattern of distribution of PACAP and PACAP type 1 receptor (PAC1) immunoreactivities were examined in the rat stomach and distal colon using a specific polyclonal antibody raised against rat/human PAC1. Western blot of the membrane preparations of NIH/3T3 cells transfected with the human PAC1 obtained by using rabbit polyclonal anti-PAC1 antibody showed a protein band with a molecular mass of approximately 50 kDa. NIH/3T3 cells transfected with the human PAC1 and incubated with the anti-PAC1 antibody displayed surface cell-type immunoreactivity, which was internalized following ligand exposure. In gastric or colonic longitudinal muscle/myenteric plexus (LMMP) whole mount preparations as well as cryostat sections, PACAP immunoreactivity was observed in cell bodies within the myenteric ganglia and nerve fibers in the muscle layers and mucosa. PAC1 immunoreactivity was confined mainly on the surface of the nerve cells. PACAP and PAC1 immunoreactivities showed a similar pattern of distribution in gastric and colonic tissues. Adjacent sections or LMMP whole mount preparations labeled with protein gene product 9.5 (PGP 9.5) revealed the neuronal identity of myenteric cells bearing PAC1. The neuronal localization of PACAP and PAC1 receptors supports their role in the neural regulation of gastric acid secretion and gastrointestinal motor function.     

Aggregate Size and Architecture Determine Microbial Activity Balance for One-Stage Partial Nitritation and Anammox

Aerobic ammonium-oxidizing bacteria (AerAOB) and anoxic ammonium-oxidizing bacteria (AnAOB) cooperate in partial nitritation/anammox systems to remove ammonium from wastewater. In this process, large granular microbial aggregates enhance the performance, but little is known about granulation so far. In this study, three suspended-growth oxygen-limited autotrophic nitrification-denitrification (OLAND) reactors with different inoculation and operation (mixing and aeration) conditions, designated reactors A, B, and C, were used. The test objectives were (i) to quantify the AerAOB and AnAOB abundance and the activity balance for the different aggregate sizes and (ii) to relate aggregate morphology, size distribution, and architecture putatively to the inoculation and operation of the three reactors. A nitrite accumulation rate ratio (NARR) was defined as the net aerobic nitrite production rate divided by the anoxic nitrite consumption rate. The smallest reactor A, B, and C aggregates were nitrite sources (NARR, >1.7). Large reactor A and C aggregates were granules capable of autonomous nitrogen removal (NARR, 0.6 to 1.1) with internal AnAOB zones surrounded by an AerAOB rim. Around 50% of the autotrophic space in these granules consisted of AerAOB- and AnAOB-specific extracellular polymeric substances. Large reactor B aggregates were thin film-like nitrite sinks (NARR, <0.5) in which AnAOB were not shielded by an AerAOB layer. Voids and channels occupied 13 to 17% of the anoxic zone of AnAOB-rich aggregates (reactors B and C). The hypothesized granulation pathways include granule replication by division and budding and are driven by growth and/or decay based on species-specific physiology and by hydrodynamic shear and mixing.In the last few years, autotrophic nitrogen removal via partial nitritation and anoxic ammonium oxidation (anammox) has evolved from lab- to full-scale treatment of nitrogenous wastewaters with a low biodegradable organic compound content, and this evolution has been driven mainly by a significant decrease in the operational costs compared to the costs of conventional nitrification and heterotrophic denitrification (11, 23). Oxygen-limited autotrophic nitrification and denitrification (OLAND) is one of the autotrophic processes used and is a one-stage procedure; i.e., partial nitritation and anammox occur in the same reactor (30). The “functional” autotrophic microorganisms in OLAND include aerobic ammonium-oxidizing bacteria (AerAOB) and anoxic ammonium-oxidizing bacteria (AnAOB). With oxygen, AerAOB oxidize ammonium to nitrite (nitritation), and with the nitrite AnAOB oxidize the residual ammonium to form dinitrogen gas and some nitrate (anammox). Additional aerobic nitrite oxidation to nitrate (nitratation) by nitrite-oxidizing bacteria (NOB) lowers the nitrogen removal efficiency, but it can, for instance, be prevented at low dissolved oxygen (DO) levels because the oxygen affinity of AerAOB is higher than that of NOB (16). Reactor configurations for the OLAND process can be based on suspended biomass growing in aggregates, like that in a sequencing batch reactor (SBR) (37) or a gas lift or upflow reactor (32). For suspended-growth systems there are two important challenges: biomass retention and equilibrated microbial activities.High biomass retention efficiency is a prerequisite in anammox technologies because of the slow growth of AnAOB (33). In suspended biomass systems, settling properties determine the retention of biomass and are related to the microbial aggregate morphology (floc or granule) and size. Granules can be defined as compact and dense aggregates with an approximately spherical external appearance that do not coagulate under decreased hydrodynamic shear conditions and settle significantly faster than flocs (18). Toh and coworkers calculated a lower sludge volume index for aerobic granules than for aerobic flocs and also showed that there was an increase in the settling velocity with increasing granule size (35). Hence, in terms of physical properties, large granules are preferable for suspended-growth applications.OLAND aggregate size not only influences settling properties but also affects the proportion of microbial nitrite production and consumption; lower AerAOB activity and higher AnAOB activity were observed with larger aggregates (25, 37). Theoretically, a microbial aggregate with equal nitrite production and nitrite consumption can remove ammonium autonomously, because of its independence from other aggregates for acquisition and conversion of nitrite. Hence, with an increasing aggregate size and thus with a decreasing ratio of nitrite production to nitrite consumption, three functional categories of aggregates can be distinguished: nitrite sources, autonomous nitrogen removers, and nitrite sinks. Because minimal nitrite accumulation is one of the prerequisites for high nitrogen removal efficiency in OLAND reactors, the presence of excess small aggregates is undesirable (9, 37).Although large granular aggregates are desirable for biomass retention and activity balance, so far no formation mechanisms have been proposed for OLAND granules, in contrast to the well-studied anaerobic (13) and aerobic (1) granules. In order to determine general and environment-specific determinants for aggregate size and architecture, three suspended-growth OLAND reactors with different inoculation and operation (mixing and aeration) parameters were selected, and these reactors were designated reactors A, B, and C (Table ​(Table1).1). The first objective of this study was to gain more insight into the relationship between OLAND aggregate size, AerAOB and AnAOB abundance, and the activity balance. The second objective was to propose pathways for aggregation and granulation by relating (dis)similarities in aggregate size distribution, morphology, and architecture to differences in reactor inoculation and operation.

TABLE 1.

Overview of the three OLAND reactor systems from which suspended biomass samples were obtained

Protection against vaccinia virus challenge by CD8 memory T cells resolved by molecular mimicry

Live vaccinia virus (VV) vaccination has been highly successful in eradicating smallpox. However, the mechanisms of immunity involved in mediating this protective effect are still poorly understood, and the roles of CD8 T-cell responses in primary and secondary VV infections are not clearly identified. By applying the concept of molecular mimicry to identify potential CD8 T-cell epitopes that stimulate cross-reactive T cells specific to lymphocytic choriomeningitis virus (LCMV) and VV, we identified after screening only 115 peptides two VV-specific immunogenic epitopes that mediated protective immunity against VV. An immunodominant epitope, VV-e7r130, did not generate cross-reactive T-cell responses to LCMV, and a subdominant epitope, VV-a11r198, did generate cross-reactive responses to LCMV. Infection with VV induced strong epitope-specific responses which were stable into long-term memory and peaked at the time virus was cleared, consistent with CD8 T cells assisting in the control of VV. Two different approaches, direct adoptive transfer of VV-e7r-specific CD8 T cells and prior immunization with a VV-e7r-expressing ubiquitinated minigene, demonstrated that memory CD8 T cells alone could play a significant role in protective immunity against VV. These studies suggest that exploiting cross-reactive responses between viruses may be a useful tool to complement existing technology in predicting immunogenic epitopes to large viruses, such as VV, leading to a better understanding of the role CD8 T cells play during these viral infections.     

Immobilization and characterization of benzoylformate decarboxylase from Pseudomonas putida on spherical silica carrier

If an adequate biocatalyst is identified for a specific reaction, immobilization is one possibility to further improve its properties. The immobilization allows easy recycling, improves the enzyme performance, and it often enhances the stability of the enzyme. In this work, the immobilization of the benzoylformate decarboxylase (BFD) variant, BFD A460I-F464I, from Pseudomonas putida was accomplished on spherical silica. Silicagel is characterized by its high mechanical stability, which allows its application in different reactor types without restrictions. The covalently bound enzyme was characterized in terms of its activity, stability, and kinetics for the formation of chiral 2-hydroxypropiophenone (2-HPP) from benzaldehyde and acetaldehyde. Moreover, temperature as well as pressure dependency of immobilized BFD A460I-F464I activity and enantioselectivity were analyzed. The used wide-pore silicagel shows a good accessibility of the immobilized enzyme. The activity of the immobilized BFD A460I-F464I variant was determined to be 70% related to the activity of the free enzyme. Thereby, the enantioselectivity of the enzyme was not influenced by the immobilization. In addition, a pressure-induced change in stereoselectivity was found both for the free and for the immobilized enzyme. With increasing pressure, the enantiomeric excess (ee) of (R)-2-HPP can be increased from 44% (0.1 MPa) to 76% (200 MPa) for the free enzyme and from 43% (0.1 MPa) to 66% (200 MPa) for the immobilized enzyme.     

Sustained release of an anti-glaucoma drug: demonstration of efficacy of a liposomal formulation in the rabbit eye

Topical medication remains the first line treatment of glaucoma; however, sustained ocular drug delivery via topical administration is difficult to achieve. Most drugs have poor penetration due to the multiple physiological barriers of the eye and are rapidly cleared if applied topically. Currently, daily topical administration for lowering the intra-ocular pressure (IOP), has many limitations, such as poor patient compliance and ocular allergy from repeated drug administration. Poor compliance leads to suboptimal control of IOP and disease progression with eventual blindness. The delivery of drugs in a sustained manner could provide the patient with a more attractive alternative by providing optimal therapeutic dosing, with minimal local toxicity and inconvenience. To investigate this, we incorporated latanoprost into LUVs (large unilamellar vesicles) derived from the liposome of DPPC (di-palmitoyl-phosphatidyl-choline) by the film hydration technique. Relatively high amounts of drug could be incorporated into this vesicle, and the drug resides predominantly in the bilayer. Vesicle stability monitored by size measurement and DSC (differential scanning calorimetry) analysis showed that formulations with a drug/lipid mole ratio of about 10% have good physical stability during storage and release. This formulation demonstrated sustained release of latanoprost in vitro, and then tested for efficacy in 23 rabbits. Subconjunctival injection and topical eye drop administration of the latanoprost/liposomal formulation were compared with conventional daily administration of latanoprost eye drops. The IOP lowering effect with a single subconjunctival injection was shown to be sustained for up to 50 days, and the extent of IOP lowering was comparable to daily eye drop administration. Toxicity and localized inflammation were not observed in any treatment groups. We believe that this is the first demonstration, in vivo, of sustained delivery to the anterior segment of the eye that is safe and efficacious for 50 days.