Expansion of Auxiliary Activity Family 5 sequence space via biochemical characterization of six new copper radical oxidases.

Bacterial and fungal copper radical oxidases (CROs) from Auxiliary Activity Family 5 (AA5) are implicated in morphogenesis and pathogenesis. The unique catalytic properties of CROs also make these enzymes attractive biocatalysts for the transformation of small molecules and biopolymers. Despite a recent increase in the number of characterized AA5 members, especially from subfamily 2 (AA5_2), the catalytic diversity of the family as a whole remains underexplored. In the present study, phylogenetic analysis guided the selection of six AA5_2 members from diverse fungi for recombinant expression in Komagataella pfaffii (syn. Pichia pastoris) and biochemical characterization in vitro. Five of the targets displayed predominant galactose 6-oxidase activity (EC 1.1.3.9), and one was a broad-specificity aryl alcohol oxidase (EC 1.1.3.7) with maximum activity on the platform chemical 5-hydroxymethyl furfural (EC 1.1.3.47). Sequence alignment comparing previously characterized AA5_2 members to those from this study indicated various amino acid substitutions at active site positions implicated in the modulation of specificity.IMPORTANCEEnzyme discovery and characterization underpin advances in microbial biology and the application of biocatalysts in industrial processes. On one hand, oxidative processes are central to fungal saprotrophy and pathogenesis. On the other hand, controlled oxidation of small molecules and (bio)polymers valorizes these compounds and introduces versatile functional groups for further modification. The biochemical characterization of six new copper radical oxidases further illuminates the catalytic diversity of these enzymes, which will inform future biological studies and biotechnological applications.

Carbon-limited fed-batch production of medium-chain-length polyhydroxyalkanoates by a phaZ-knockout strain of Pseudomonas putida KT2440.

A medium-chain-length poly-3-hydroxyalkanote (MCL-PHA) depolymerase knockout mutant of Pseudomonas putida KT2440 was produced by double homologous recombination. A carbon-limited shake-flask study confirmed that depolymerase activity was eliminated. Lysis of both mutant and wild-type strains occurred under these conditions. In carbon-limited, fed-batch culture, the yield of unsaturated monomers from unsaturated substrate averaged only 0.62 mol mol(-1) for the phaZ minus strain compared to 0.72 mol mol(-1) for the wild type. The mutant strain also produced more CO2 and less residual biomass from the same amount of carbon substrate. However, most results indicated that elimination of PHA depolymerase activity had little impact on the overall yield of biomass and PHA.

Splenic lymphangioma in adult patient treated with laparoscopic splenectomy: A rare case report.

Splenic lymphangioma is a benign cystic tumor that develops as a result of lymphatic vessels' congenital abnormalities. It is a rare condition that mostly occurs in children and young adults. Due to the lack of typical symptoms and signs, splenic lymphangioma is difficult to diagnose and often incidentally revealed during radiological examinations. We report a case of a 55-year-old Asian female, who presented with left upper quadrant abdominal pain in the past 3 days. She had mild upper abdominal tenderness, with no other specific findings. Abdominal contrast material-enhanced computed tomography revealed three hypodense lesions arising from a normal-sized spleen. The histologic findings after laparoscopic splenectomy demonstrated a 3-cm-diameter yellowish-white tumor made up of multiple cystic structures. Primary benign splenic tumors are exceedingly rare, especially in adults over 20. While small lesions are mostly asymptomatic, bigger lesions can cause organ compression or even rupture. Therefore, even in adults with pain in the left upper quadrant abdomen or enlarged spleen, splenic lymphangioma should be taken into account in the differential diagnosis. The case serves as an example of a rare congenital splenic tumor. Treatment of this benign splenic abnormality with laparoscopic splenectomy is a good, safe approach.

Heterotopic Pancreas in the Duodenum Diagnosed after Laparoscopic Biopsy.

Heterotopic pancreas is defined as the presence of ectopic pancreatic tissue outside boundaries of the pancreas without vascular and duct system connection with the pancreas. Ectopic locations are mostly found anywhere in the gastrointestinal tract such as the stomach (24-38%), the duodenum (9-36%), and the jejunum (0.5-27%). Clinical manifestations are not specific, vague, and misdiagnosed another digestive disease. Most cases are incidentally detected by histological examination of specimens resected for different pathologies during endoscopy, surgery, or even autopsy. We report a case of a 31-year-old man who admitted to the hospital with the reason of epigastric pain for 3 days. Clinical examination showed mild epigastric tenderness. The past medical history of patient was unremarkable. A submucosal lesion was observed in the first part of the duodenum during endoscopy. Computed tomography and endoscopic ultrasonography findings were suspected to be heterotopic pancreatic tissue. After laparoscopic surgery for biopsy, it was histologically confirmed duodenal ectopic pancreas. It is difficult to differentiate gastrointestinal pancreatic heterotopia from gastrointestinal stromal tumors, leiomyoma, or lymphomas by using endoscopy because ectopic tissue is mostly located in the submucosal layer. In addition, rare cases of ectopic pancreatic tissue transform malignancy. Surgical treatment should be considered to take adequate tissue samples for biopsy or resect the lesions in symptomatic patients. Duodenal pancreatic heterotopia is an uncommon congenital malformation and most patients are asymptomatic. Histological examination is essential to exclude malignant lesions and to have an appropriate treatment.

Balo's Concentric Sclerosis Mimicking Tumor on Magnetic Resonance Imaging in a Young Patient.

Balo's concentric sclerosis (BCS) is a rare demyelinating disease known as Multiple Sclerosis (MS) lesion type III. It is a disease of the white matter of the brain characterized by a round lesion with variable concentric myelinated and demyelinated layers, appearing as "onion bulb." We present a case of BCS and discuss the imaging findings and management strategies of this disease. A 26-y-old male developed headache, weakness, and numbness of limbs. Magnetic resonance imaging (MRI) showed concentric lamellar like demyelinating lesions at the subcortical regions. The patient's neurological symptoms were consistent with the MRI findings.

A Case of Arteriovenous Fistula After Kidney Trauma Mimicking Tumor.

Renal arteriovenous fistulas are rare complications of kidney injury that are usually caused by penetrating or blunt abdominal trauma, percutaneous or open biopsy, or surgery. We report a case of renal arteriovenous fistula after blunt abdominal trauma of a male patient who had traffic accidents. Computed tomography images show arteriovenous fistula lesion mimicking the tumor of the renal pelvis. Through this case, we present how to identify and avoid being confused in diagnosis as well as introduce its clinical manifestations, imaging, and treatment.

Intracranial Neurenteric Cyst in a Patient with Acute Unilateral Thalamic Infarction.

Intracranial neurenteric cysts are rare congenital lesions that can be mistaken for other lesions. They may contain mucous or serous glands, smooth muscle, lymphoid tissue and components of connective tissue. We report a case of neurenteric cyst which was detected accidentally by diagnostic imaging in the context of a thalamus infarct in a 45-year-old woman. We also discuss the results of a brief literature review and the pathological findings, imaging spectrum, evaluation and management of neurenteric cysts and thalamic infarctions. LEARNING POINTS: Neurenteric cysts are a rare type of foregut duplication cyst that are classified as intracranial or spinal and are associated with central nervous system abnormalities.Neurenteric cysts are usually benign and slow-growing, so conservative treatment can be provided if there are no symptoms.Thalamic stroke may be caused by arterial or venous infarction.Cardioembolism is the most common cause of thalamus infarction; variations in blood supply to the thalamus should be investigated in affected patients.

Metabolic engineering and characterization of phaC1 and phaC2 genes from Pseudomonas putida KCTC1639 for overproduction of medium-chain-length polyhydroxyalkanoate.

Two PHA synthase phaC1 and phaC2 genes cloned from the new strain Pseudomonas putida KCTC1639 were metabolically engineered for the overproduction of medium-chain-length polyhydroxyalkanoate (mcl-PHA). The overexpressed phaC1 and phaC2 genes in P. putida KCTC1639 were compared in terms of the biosynthesis of mcl-PHA, fatty acid assimilation, distribution of 3-hydroxylacyl monomer units, granular morphology, and thermophysical properties of the accumulated mcl-PHA. The biosynthesis of mcl-PHA was enhanced only by the overexpressed phaC1 gene up to 2.86-fold, in contrast, the phaC2 gene did not activate the biosynthesis of mcl-PHA. The overexpressed phaC1 gene tended to form enlarged, high molecular weight, and lower crystalline mcl-PHA granules, whereas the amplified phaC2 gene induced the fragmentation of mcl-PHA into a few small-sized granules. The transformant P. putida KCTC1639 overexpressing the phaC1 gene encoding PHA synthase I was cultivated by pH-stat fed-batch cultivation, and the concentration and content of mcl-PHA increased up to 8.91 g L-1 and 70.5%, respectively.

Comparative effect of overexpressed phaJ and fabG genes supplementing (R)-3-hydroxyalkanoate monomer units on biosynthesis of mcl-polyhydroxyalkanoate in Pseudomonas putida KCTC1639.

phaJ and fabG genes encoding (R)-specific 2-enoyl-CoA hydratase and 3-ketoacyl-acyl carrier protein reductase, respectively, were cloned from Pseudomonas putida KCTC1639 and amplified in the parent strain to achieve oversupplementation of (R)-3-hydroxyalkanoate monomer units for the biosynthesis of medium-chain-length polyhydroxyalkanoate (mcl-PHA). The comparative effect of the overexpressed fabG and phaJ genes in P. putida KCTC1639 on the biosynthesis of mcl-PHA and the cell growth were elucidated. Overexpression of phaJ enhanced the biosynthesis of mcl-PHA, increasing its content and concentration from 18% to 27% and 0.38 to 0.51 g/l, respectively. Conversely, fabG overexpression tended to depress the biosynthesis of mcl-PHA, possibly due to the reversible conversion of (R)-3-hydroxyalkanoate monomer units into 3-ketoacyl-CoA.

Utilization of fadA knockout mutant Pseudomonas putida for overproduction of medium chain-length-polyhydroxyalkanoate.

The fadBA operon in the fatty acid beta-oxidation pathway of P. putida KCTC1639 was blocked to induce a metabolic flux of the intermediates to the biosynthesis of medium chain-length PHA (mcl-PHA). Succinate at 150 mg l(-1) stimulated cell growth and also the biosynthesis of medium chain-length-polyhydroxyalkanoate. pH-stat fed-batch cultivation of the fadA knockout mutant P. putida KCTC1639 was carried out for 60 h, in which mcl-PHA reached 8 g l(-1) with a cell dry weight of 10.3 g l(-1).