diff --git a/bin/create_metabinner_bins.py b/bin/create_metabinner_bins.py
index 120a65187..9396a101d 100755
--- a/bin/create_metabinner_bins.py
+++ b/bin/create_metabinner_bins.py
@@ -1,16 +1,23 @@
 #!/usr/bin/env python
 
-## Originally written by Hesham Almessady (@HeshamAlmessady) and Adrian Fritz (@AlphaSquad) in https://github.com/hzi-bifo/mag and released under the MIT license.
+## Originally written by Hesham Almessady (@HeshamAlmessady) and Adrian Fritz (@AlphaSquad)
+# in https://github.com/hzi-bifo/mag and released under the MIT license.
 ## See git repository (https://github.com/nf-core/mag) for full license text.
 
-import sys
+import gzip
+import io
 import os
+import sys
+
 from Bio import SeqIO
 
+
 def main():
     # Argument parsing
     if len(sys.argv) != 6:
-        print("Usage: python create_metabinner_bins.py <binning_file> <fasta_file> <output_path> <prefix> <length_threshold>")
+        print(
+            "Usage: python create_metabinner_bins.py <binning_file> <fasta_file> <output_path> <prefix> <length_threshold>"
+        )
         sys.exit(1)
 
     binning = sys.argv[1]
@@ -19,27 +26,39 @@ def main():
     prefix = sys.argv[4]
     length = int(sys.argv[5])
 
-    # Create output directory if it doesn't exist
+    root = os.path.dirname(os.path.normpath(path)) or "."
     os.makedirs(path, exist_ok=True)
 
-    # Load binning data into a dictionary
-    Metabinner_bins = {}
-    with open(binning, 'r') as b:
+    metabinner_bins = {}
+    with open(binning, "r") as b:
         for line in b:
-            contig, bin = line.strip().split('\t')
-            Metabinner_bins[contig] = bin
+            contig, bin = line.strip().split("\t")
+            metabinner_bins[contig] = bin
+
+    handles = {}
+
+    def get_handle(dest_dir, fname):
+        key = os.path.join(dest_dir, fname)
+        if key not in handles:
+            raw = open(key + ".gz", "wb")
+            gz = gzip.GzipFile(fileobj=raw, mode="wb", mtime=0)
+            handles[key] = (io.TextIOWrapper(gz, encoding="utf-8"), raw)
+        return handles[key][0]
 
-    # Process the input fasta file
     with open(fasta) as handle:
         for record in SeqIO.parse(handle, "fasta"):
-            if len(record) < length:
-                f = prefix + ".tooShort.fa"
-            elif record.id not in Metabinner_bins:
-                f = prefix + ".unbinned.fa"
+            if len(record) <= length:
+                out = get_handle(root, prefix + ".tooShort.fa")
+            elif record.id not in metabinner_bins:
+                out = get_handle(root, prefix + ".unbinned.fa")
             else:
-                f = prefix + "." + Metabinner_bins[record.id] + ".fa"
-            with open(os.path.join(path, f), 'a') as out:
-                SeqIO.write(record, out, "fasta")
+                out = get_handle(path, prefix + "." + metabinner_bins[record.id] + ".fa")
+            SeqIO.write(record, out, "fasta")
+
+    for text, raw in handles.values():
+        text.close()
+        raw.close()
+
 
 if __name__ == "__main__":
     main()
diff --git a/modules/local/metabinner_bins/main.nf b/modules/local/metabinner_bins/main.nf
index 14eb96355..efa2621a5 100644
--- a/modules/local/metabinner_bins/main.nf
+++ b/modules/local/metabinner_bins/main.nf
@@ -25,17 +25,12 @@ process METABINNER_BINS {
     # unzip membership file
     zcat ${membership} > membership.tsv
 
-    # collect bins & un-binned fractions
     create_metabinner_bins.py \\
         membership.tsv \\
         ${fasta} \\
         ./bins \\
         ${prefix} \\
         ${min_contig_size}
-    find ./bins/ -name "*.fa" -type f | xargs -t -n 1 bgzip -@ ${task.cpus}
-
-    # zip contig fractions
-    find ./bins/ -name "*[tooShort,unbinned].fa.gz" -type f -exec mv {} . \\;
 
     cat <<-END_VERSIONS > versions.yml
     "${task.process}":
diff --git a/subworkflows/local/binning_metabinner/main.nf b/subworkflows/local/binning_metabinner/main.nf
index 2adbdd888..562396f09 100644
--- a/subworkflows/local/binning_metabinner/main.nf
+++ b/subworkflows/local/binning_metabinner/main.nf
@@ -11,22 +11,18 @@ workflow BINNING_METABINNER {
     main:
     ch_versions = channel.empty()
 
+    ch_assembly = ch_input.map { meta, assembly, _depths -> [meta, assembly] }
+
     // produce k-mer composition table
     METABINNER_KMER(
-        ch_input
-            .map { meta, assembly, _depths ->
-                [meta, assembly]
-            },
+        ch_assembly,
         params.min_contig_size
     )
     ch_versions = ch_versions.mix(METABINNER_KMER.out.versions)
 
     // extract contigs over length threshold
     METABINNER_TOOSHORT(
-        ch_input
-            .map { meta, assembly, _depths ->
-                [meta, assembly]
-            },
+        ch_assembly,
         params.min_contig_size
     )
     ch_versions = ch_versions.mix(METABINNER_TOOSHORT.out.versions)
@@ -41,8 +37,7 @@ workflow BINNING_METABINNER {
 
     // extract bin sequences
     METABINNER_BINS(
-        ch_input.map { meta, assembly, _depths -> [meta, assembly] }
-            .join(METABINNER_METABINNER.out.membership),
+        ch_assembly.join(METABINNER_METABINNER.out.membership),
         params.min_contig_size
     )
     ch_versions = ch_versions.mix(METABINNER_BINS.out.versions)